fishE

Problems Down South!

26 posts in this topic

Hello everyone, new to this site but have been a lurker for some time now.

 

I’m running into some confusing problems with my somewhat-new AP system, and hopefully you guys can set me straight (or, at least, in the right direction!).

 

Background and System Specs:

 

I had been thinking about and researching building an AP system for about 3 years, and finally took the plunge this winter and spring.

 

So earlier this year I built a 500 square-foot enclosed hoop-house style greenhouse (solexx side walls) with a (maximum) 950-gallon in-ground tank (8 ‘ x 6’ x 4’ deep) along with 8 (2 rows of 4) growbeds, each bed being about 24 square feet (8’ x 3’) and a foot or so deep…..so each grow bed will hold about 180 gallons (empty), and since each grow bed is filled with #57 gravel (granite), so let’s say that each grown bed can hold about 90 gallons of water when full.

 

Each row of 4 beds is fed by its own submerged water pump, and both pumps are run off a single recycling timer (about 9 minutes on, then 1 minute off, etc.  24/7).    The beds are flood-and-continuous drain (no siphons), and the pumps can deliver enough volume to basically fill each bed about 3 times during each 10-minute “ON†fill cycle.

 

The water drains back from each row (of 4) grow beds thru a 3†common drain, and empties into the fish tanks (from a height of about 1-foot above the height of the water’s surface).

 

Aeration:   besides the above water-drainback into the tank, there are 2 cycles within each hour (of 6 cycles) where the water pump’s output is being diverted into a 3-foot long, above-water spray bar or an under-water venturi “air educatorâ€.     Thus for 20 minutes out of each hour, the water pumps are actually being used for aeration purposes:

 

Water Pump Cycle #1 (9 minutes on, 1 minute off):  fill grow bed #1

Water Pump Cycle #2 (9 minutes on, 1 minute off):  fill grow bed #2

Water Pump Cycle #3 (9 minutes on, 1 minute off):  aerate the fish tank with spray bar and venturi educator

Water Pump Cycle #4 (9 minutes on, 1 minute off):  fill grow bed #3

Water Pump Cycle #5 (9 minutes on, 1 minute off):  fill grow bed #4

Water Pump Cycle #6 (9 minutes on, 1 minute off):  aerate the fish tank with spray bar and venturi educator

And now we’re back to Cycle #1 above.

 

And remember, there’s two water pumps, each one performing the above actions simultaneously, and each pump services 4 (of 8) grow beds.

 

 

In addition to the above, there is a diaphragm type air-pump (again, running 24/7) feeding two 8†round air stones, total flow rate of the stones is about 20 lpm each (total of 40 LPM, about 1.5 cfm).

 

 

 

Fish:  about 125 blue tilapia, introduced on April 30th as fingerlings, now about 6-8†in length.     They seem healthy and happy and feed like ravenous sharks (either once or twice a day, depending on nitrite levels)

 

Feed:  a mixture of various sizes and brands have been used over time, including Purina Aquamax, Cargill tilapia feed, and Premium Fish Food Co. fingerling, intermediate, and growout pellets.   

 

Plants:   a mix of herbs (LOTS of basil), 8 tomato plants (now full grown), 6 pepper plants (full grown), some Brussel sprouts, 2 cucumbers, 2 squash, some lettuce, a few other leafy greens.    Have about 6 of the grow beds fully occupied, and two basically empty.

 

Chemicals and chemistry:    have a continuous monitoring (Bluelab) pH - water temp - TDS/EC meter, and a continuous monitoring (Hanna Instruments) D.O. meter.      Chemicals are tested daily with API freshwater titration (liquid) tests for Ammonia, Nitrite, and Nitrates.    Iron, calcium, and magnesium are tested for weekly using a Hanna photometric tester.

 

The system was pre-cycled before fish were introduced for about 2 weeks.     Water temps have been maintained since inception at between 78 - 82F.    pH started out in the 7.4 - 7.6 range, and has slowly but continuously dropped over time after fish were added, and are now all the way down to the 6.0 - 6.1 level…….and since about a month or so ago, it requires CONSTANT hyrdroxide and/or carbonate supplementation (on a thrice-daily basis) to maintain the pH in the 6.3 - 6.5 range.    The water always wants to trend back  down into the high 5’s or very low 6’s if left untreated for any significant (12 hours) length of time.

 

Ammonia:  has basically always been in the .25 - .50ppm range. occasionally goes up into the 1ppm range after heavy feedings.

 

Nitrites:   has basically always been in the 0 -.50ppm range, although lately, as I have been increasing the fish feed rate (1/2 to 1 pound per day), the nitrites always spike up to 1 - 2+ ppm about 6 hours after feeding, and then take about 12 hours to return down to the 0 - .50 mg/L range.

 

Nitrates:  has basically always been in the 80-160ppm range ever since the fish grew past the fingerling stage (it’s rather difficult to get more precise readings of nitrates using the API test kit, and 160ppm is the maximum that it goes up to, so for all I know it may be higher).

 

Iron:  supplement with chelated iron, runs 1 - 1.5ppm

 

Magnesium:  supplement with magnesium sulfate and/or dolomitic lime, runs in the 10 - 15 ppm range.

 

Calcium:   supplement as part of the pH control process using dolomitic lime, calcium carbonate, and (mostly) calcium hydroxide.    Runs 20 - 40ppm

 

Potassium:  supplement as part of the pH control process using potassium hydroxide, as well as occasional additions of Kelp Extract and a Humic/Fulvic acid solution (which contains a little bit of potassium).    Potassium ranges anywhere from 40 - 80 ppm.

 

 

 

Okay, so much for background, here is where I’m having issues, and am pretty clueless about what steps to take:

 

 

Plant and fruit growth:   LOTS (I mean a truly impressive amount, and since I soil-farm, too, I feel that I have a good basis of comparison) of leaf and stem growth on the fruiting plants (tomatoes, cukes, etc.).   I’m talking about nuclear levels of growth, I’ve never seen squash leaves this big.  :sword:    Tomatoes are big and bushy.   Leafy greens (lettuce and kale) growth has been “okayâ€, nothing spectacular.    Herbs (basils) have been mighty impressive, too.

 

 

Problems:

 

Plants:  almost no or nil fruit production.     Using the same batch of tomato seedlings (bought a tray of 12 from a nursery), the output from the in-soil plants out-produces the AP plants by a factor of about 50-to-1.       Cucumbers:   soil-based plants are out-producing the AP plants by a factor of 50-to-1.     Squash:    Have not got a single squash from the AP plants.    Peppers:  these I have no direct comparison for, and although the peppers are definitely producing (jalapeno), I might get a whole pound per week (from 6 plants).    Herbs (mainly basil):   super productive, much more than I could ever consume!     Brussel sprouts:   none (although to be fair, my outdoor soil crop has not produced any, either………).

 

 

Oxygen:    I can never seem to get oxygen levels up to “recommended†levels of 6+ ppm.    Typically, they are in the 3 - 4.5 ppm level (obviously, when the water is cooler, the DO is at the “higher end†of that range, but it varies a lot even then),     After feeding, of course DO drops like a rock (by about a point of so), but then gradually rebounds.    15 minutes or so after feeding, some/many of the tilapia will gather along the outer walls of the tank and “gulp†air for about 5 minutes or so…..but they never gather around the water inlet (from the drain pipe) nor do they ever exhibit this behavior except after feedings.

 

There does not seem to be any significant algae build-up (the water remains somewhat translucent dark-brownish from the regular iron supplementation, and the greenhouse has a shade cloth over the fish tank end).     Occassionally I see some minor green build-up (coating) on the white PVC pipes that are submersed within the tank, but never in the growbeds (the top layer doesn’t get wet, except where the water from the pumps discharges onto a small area of the surface, and yes, there is a small “skin†of algae in those places, but it is small…maybe 1 square foot per growbed, max).

 

 

 

I’m sorry to be so long-winded, but like I said, I’m somewhat at wit’s end here.   I’m ASSUMING (whoa!) that the nitrification process is working well, since I see the low ammonia levels, nitrite spikes and retreats, and high nitrate levels, as well as the continual falling pH levels.    I’m fairly comfortable with a good nutrient mix, although the TDS levels (EC x 700) is getting higher and higher 200, then 300, then 400, now closing in on 500ppm).

 

 

I have NOT done any water “changesâ€, but typically have to add about 100 gallons a week of de-chlorinated water to make up for evaporative and other water losses (there is a small 5-gallon-a-day leak in one the grow beds drains, arrrghhhh......).

 

 

Again, apologizies for the length of this post, but I wanted to cover all the bases so that no one needs to divert time to playing a guessing game!

 

 

So what am I doing wrong, and what do I need to start doing?

 

 

THANKS!

Edited by fishE (see edit history)

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Hi FishE,

 

Welcome to APN.....and congratulations on one of the most coherent (and useful) first posts that I've ever seen on an aquaponics forum.

 

It's so much easier when people with issues spell out their circumstances rather than the more frequent approach that goes something like "My fish are dying.  What am I doing wrong."

 

Let me take a while to digest your post.....and to do your efforts justice.....and I'll be back.

 

Gary

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Hello Gary, thanks for the note and kind words.   Took me 12 edits to get it right!

 

A few items that I forgot to list was outside temps and inside-the-greenhouse temps.   I'm in the southern US, so from inception (May) it's been anywhere from 65-70F up to 100+ for the few last weeks (both internal and external, even with the inside and exhaust fans running full blast, and the water-soaked evaporative "cool wall" being run constantly), along with sometimes torturous humidity levels (90%+, but more usually in the 60 - 80% range).   Evenings get down into the low 60's or mid 70's F, and typically pretty dry humidity-wise.

 

I don't measure phosphate levels or hardness very frequently.   The last readings that I have for these (measured via API test kits) are:

 

KH:   35.8ppm

GH:  71.6 ppm

Phosphate:  .25 - .50ppm

 

 

I just went out and looked at the DO meter:  1.8mg/L at 23:00 hours.    All the fish should be on their way to Heaven, but again, no surface gasping or other odd behaviors.    Maybe my meter is out of whack, but I just changed membranes and re-calibrated about a week ago.     It's always odd, when the pumps are in Cycles #3 and #6 (the spray-bar and eductor cycles), the DO levels always DROP when these cycles are running, and then recover afterwards......   I'm REALLY confused about the DO issue, from what I've read and researched, there should be plenty of oxygenation in this system, but maybe I'm over-looking something very basic (as in "simple", not as in "alkaline").......ha-ha, bad joke, I know.

 

Thanks.

Edited by fishE (see edit history)

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BTW, Welcome to APN.

 

Kh is on the low side, I strive between 60-80 ppm..    The oxygen levels are problematic too.   A question that comes to my mine  is whether  the pump circulating all the water from the tank or  just getting water from the same section of  the tank over and over?   

 

How big are your pumps?

 

I have to say you have presented a perplexing puzzle.

Edited by Ravnis (see edit history)

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Hello Ravnis, thanks for the response and welcome.

 

Hardness:

 

I re-checked the GH and KH last night, and the readings are:

 

GH:  215ppm

KH:    36ppm

 

What's the best way to increase KH, just start using carbonate compounds for pH adjustment?   

 

 

Aeration:

 

The DO levels are perplexling to me too.    Today I drafted into use my back-up air pump to go along with my normal pump.   So I'm now running two of these pumps 24/7, the #9730 model:

 

http://pentairaes.com/low-cost-outdoor-air-pumps.html

 

and they are hooked up to 3 (total) 12" x 1.5" x 1.5" air stones:

 

http://shop.bubblemacairdiffusers.com/Air-Diffuser-15-x-15-x-12-w-3-8-poly-barb-Medium-Pore-00122.htm

 

 

 

They make a really impressive stream of bubbles, breaking the surface and "raising" the water level about an inch or so where they come up.   The entire surface of the tank stays in some state of agitation due to the action of the air stones.

 

Of course the above is in addition to:

 

- returning water from two drain pipes (one drain for each "set" of 4 growbeds).     These drains are in constant action, and of course the rate of flow changes from "a bit"  (maybe 4 gallons per minute) to "a lot"  (perhaps 20 gallons a minute) per drain.   BTW the drain waters are passing thru a 90-degree elbow (3", just like the drain pipe) just before exiting the drain, and these elbow are "tilted" to discharge the water at a 45-degree angle to the water's surface (instead of just pointing straight down at the water's surface), and they are also directed towards the tank's long wall centerline, thus the drain water from the growbeds is entering the tank about as far away from the water pumps as is possible.

 

- 2 x 10 minute water pump cycles (i.e. 20 minutes per hour) using a 1" underwater venturi educator:

 

http://mazzei.net/venturi_injectors/

 

- 2 x 10 minute water pump cycles (again, total of 20 minutes per hour) using a 3" long PVC home-made above-water spray bar (16 x 1/4" holes along the entire length, about 1-foot above the surface, basically pointing straight towards the surface).    The stream of water from each of the 16 holes penetrates the water surface a least 6" and certainly creates an impressive level of bubbles at the surface and up to 6" deep.

 

 

Besides going to an oxygen concentration system, I'm not sure what else to do!    I would have been willing to bet that this much (and types) of aeration would results in LOTS of DO, but I guess not.   Water temps are typically around 80F (between 78 - 82F depending on time of day, and outside temps).  

 

 

Just for gits and shiggles, this afternoon I took the DO probe and started measuring DO levels at different spots within the tank (and at different levels within the tank, tank currently has about 600 gallons in it, and that is about 36-40" of water depth).      Even placing the meter directly within the stream of air bubbles from the airstones, best I could get was about 4.8ppm.     Moving it away from the airstone flow about 2 feet reduces the DO to about 2.8ppm.    Same situation with the water from the spray bars, much higher right under the water being injected (4.5ppm) and drops like a rock a few inches away.

 

I'm just amazed (and more than a little bit jealous) when I read of people who have 6, 7, or 8ppm of DO.     Unless those levels are with water at 65F or something, I just don't see or understand what I'm doing wrong/what I need to change.

 

But again, I will say that the fish don't really show any of the signs of oxygen deprivation (surface gasping, lethargy, poor appetite ---- they feed like piranha! ---- EXCEPT right after feeding, when they will gather in the corners of the tank and do the surface gasp thing for about 5 minutes or so.    This occurs no matter how much or when I feed them.

 

 

 

Water pumps:

 

Using two of the PWM3900 mag-drive pumps, one pump feeds each of one set of 4 growbeds, 1 growbed at a time (the outlet of the pump goes up to a 6-port indexing valve, 1" PVC tubing from the pump to the indexer, and 1" PVC from the indexer to each of the 4 growbeds that pump is serving):

 

http://www.lg-outdoor.com/p/pwm3900?pp=12

 

Pondmaster PWM3900 mag-drive pumps:

Model:  PWM3900

Item # 76076

Watts:  198-260W

Max Height:  19'

 

GPH @ Total Head Pressure of:

4050 @ 1 foot

3300 @ 5 feet

2280 @ 10 feet

1270 @ 15 feet

 

 

Each pump is located centrally along the short "side"  of the tank (tank is 6' x 8') , and about 1' off of that short wall.

 

Actual water flow seems to be about 10-12 GPM per pump, I can get more specific measurements if needed.

 

 

 

Algae:

 

Like I mentioned, I can't "see" any algae, besides the very small amount of slimey green stuff that appears on the surface of gravel where the water discharges into the grow beds.   I wouldn't really know what to look for in the tank.     The water is (and always has been) a sort of amber/dark brown translucent color, the white PVC pipe from the pump to the indexing valve is clearly visible its entire length from the pump to where it breaks the water's surface.    These white pipes have a slight, thin, blotchy covering of green on them for part of their length; I assume that's algae.   I can see nothing (no solids) within the tank water.

Edited by fishE (see edit history)

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I'm a fan of bicarbonates and use potassium bicarbonate myself.     I don't think algae is the problem.     I would back off on feeding till the ph stabilizes.  probably about 1/2 pound a day until oxygen levels stabilize.   If co2 is not outgassing enough it will drive the ph down and create for lack of  a better term and oxygen debt.

Edited by Ravnis (see edit history)

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Hi Ravnis, thanks for the input.   I do have some pot bicarb (as well as calcium carbonate), I've always tended to use hydroxides to manage pH (mainly based on what Nate Storey says, although I realize that his statements on the subject of carbonate use mainly applies to high-pH systems).      I've always noticed that using calcium carbonate (2 tablespoons per tank) rarely budges pH (maybe 0.1) whereas I can shoot pH to the moon (1.0 or more increase, and rather instantaneously) when using a similar amount of hydroxides (pickling lime or 99% food grade KOH).     Another reason why I've stuck to hydroxides.....

 

I know the little fishies output CO2, how does it turn into an acid (I assume carbonic acid) in the water?

 

I've always assumed (I know, bad move!) that since the nitrification cycle seems to be performing well (which I have again assumed it actually IS doing well because of the plant GROWTH --- even with lack of significant fruiting ---- and due to the nitrites moving up-and-down in tandem with feedings, and with the significant nitrate levels) and that this good level of nitirification was the cause of the pH movements.

 

I actually had a conversation with Nate about the carbonates, and he said "don't use them if you don't have to", and so I asked him where the bacteria would get all their carbon from w/o carbonate use, and he immediately replied that there was no need to worry about that, the CO2 provides the carbon......

 

What would cause CO2 to not outgas?   Anyway for me to confirm (measure?) how much CO2 is in there?   The greenhouse is ventilated pretty darn well (i.e. there is always a "breeze" blowing thru it).

 

And out of curiosity, why do you believe there is not an algae problem?    What, exactly, would I look for or notice to determine whether there is an algae problem?    Or would it be physically obvious on the water surface or water "cloudiness"?

 

Also, what problems does the low value of KH cause, and is it in any way related to the pH and/or DO  issues?

 

Thanks again for your input.    Sorry for all the newbie questions, but I am rather new to the actual "operation" (as opposed to reading "knowledge") side of things.

Edited by fishE (see edit history)

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Hi Ravnis, thanks for the input.   I do have some pot bicarb (as well as calcium carbonate), I've always tended to use hydroxides to manage pH (mainly based on what Nate Storey says, although I realize that his statements on the subject of carbonate use mainly applies to high-pH systems).      I've always noticed that using calcium carbonate (2 tablespoons per tank) rarely budges pH (maybe 0.1) whereas I can shoot pH to the moon (1.0 or more increase, and rather instantaneously) when using a similar amount of hydroxides (pickling lime or 99% food grade KOH).     Another reason why I've stuck to hydroxides.....

 

I know the little fishies output CO2, how does it turn into an acid (I assume carbonic acid) in the water?   Carbonic acid is CO2 dissolved in water.  This is one of the things the Bakki Showers or trickle towers  do well. . Nates  towers are essentially trickle towers in it's most basic sense.

 

I've always assumed (I know, bad move!) that since the nitrification cycle seems to be performing well (which I have again assumed it actually IS doing well because of the plant GROWTH --- even with lack of significant fruiting ---- and due to the nitrites moving up-and-down in tandem with feedings, and with the significant nitrate levels) and that this good level of nitirification was the cause of the pH movements.   Nitrate forming bacteria go both ways, when oxygen is plentiful they wiil convert nitrite to nitrate.  In very low conditions they do the reverse.

 

I actually had a conversation with Nate about the carbonates, and he said "don't use them if you don't have to", and so I asked him where the bacteria would get all their carbon from w/o carbonate use, and he immediately replied that there was no need to worry about that, the CO2 provides the carbon......   My understanding is that the nitrification bacteria require carbon in the form of carbonates.  There are numerous species of nitrification bacteria, so to say that all require it may not be a correct statement.

 

What would cause CO2 to not outgas?   Anyway for me to confirm (measure?) how much CO2 is in there?   The greenhouse is ventilated pretty darn well (i.e. there is always a "breeze" blowing thru it).    If the gas exchange interface does not have enough surface area then that could be the issue of high CO2 and low O2.  Based on your description of your system, I struggle to see how this is so.

 

And out of curiosity, why do you believe there is not an algae problem?    What, exactly, would I look for or notice to determine whether there is an algae problem?    Or would it be physically obvious on the water surface or water "cloudiness"?   I run a hybrid  greenwater-aquaponic system where I purposely grow algae for the tilapia.

 

Also, what problems does the low value of KH cause, and is it in any way related to the pH and/or DO  issues?  KH is a measurement of carbonate buffering capacity.  I've seen reported values from 40 ppm to 180 ppm.  My personal experience was that i was using the hydroxides and would adjust ph before I went to work and by the time I got back home it was back to where I started. I used the potassium bicarbonate mixed with vinegar in a bucket  to get the ph back down. Added that and went to having to adjust once a month or less.

 

Thanks again for your input.    Sorry for all the newbie questions, but I am rather new to the actual "operation" (as opposed to reading "knowledge") side of things.   You're welcome.  I asked similar questions when I started 7 years ago myself, so don't feel bad at all.

Edited by Ravnis (see edit history)

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Ravnis, you're great, have you thought of running for President?

 

Seriously, thanks.    Couple of follow-up questions (lots, actually, but just these for now):

 

Nitrate forming bacteria go both ways, when oxygen is plentiful they wiil convert nitrite to nitrate.  In very low conditions they do the reverse.

 

 

Wow.   No one else seems to mention that little tidbit........

 

 

 

My personal experience was that i was using the hydroxides and would adjust ph before I went to work and by the time I got back home it was back to where I started.

 

Lucky you.   My cycle runs like about 2 hours or so after raising the pH before it drops back down.......feeding or not.

 

 

 

I used the potassium bicarbonate mixed with vinegar in a bucket  to get the ph back down.

 

Why the vinegar?   Doesn't vinegar lower the pH, while the bicarbonate raises the pH?   Or were you just trying to add the bicarb w/o moving the pH?

 

 

 

 

Carbonic acid is CO2 dissolved in water.

 

So how do I get a handle or feel for whether the pH drops are caused by nitrification of just feeding and then CO2 --> carbonic acid production?     I know in one sense it "doesn't matter" the cause, but I am curious and want to add to my understanding.

 

 

Appreciate it!

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Yes, I add the vinegar to get more carbonates without doing a major adjustment of ph.   There are bacteria that convert acetic acid to carbonates, so It becomes a major carbonate boost.    Just be careful not to change ph too much at one time as it is stressful for the fish.

 

Carbonic acid is a weak acid,  with sufficient buffering in the system, it's impact will be negligible, unless you are severely overstocked.   That is also something to consider, but I think increasing the buffering capacity would be a first step.

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Okay Ravnis thanks again for the insights.  I have started today dosing some potassium bicarbonate into the water to try and get the KH level up.

 

I "solved" my DO problem today.    Seems that last time I changed the membrane on the DO meter probe, I must have slightly pinched the o-ring that seals the electrolytic solution within the membrane.......I guess as the solution got more and more contaminated with tank water, it threw the readings more and more off (and more and more variable).    Although I feel like an idiot for not discovering this issue sooner, I can't even begin to put into words what a relief it was to discover that.

 

Now, I'm still not into the 6-7-8ppm range, but at least more comfortable in the high 4's to mid 5's.    Are there any other methods of increasing DO to get it higher (besides decreasing water temps)?

 

And finally, what should I be looking at / considering to solve the "lots of plant growth but lack of fruiting" issue?

 

You guys are great, I really appreciate your help.

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I would tackle one thing at a time and get the wild ph swings under control.   I've had the same problem multiple times and adding potassium and sometimes magnesium has been the fix. So if using potassium bicarbonate to fix the ph problem, you might just fix two problems at the same time.  

 

I have to say that no two systems have the same source water, media, environmental conditions, so what works for me may not be  what works for your setup. There are common problems that are frequently troubleshot, so I believe this will help.  I look forward to an update.

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Hi FishE,

 

Welcome to APN.....and congratulations on one of the most coherent (and useful) first posts that I've ever seen on an aquaponics forum.

 

It's so much easier when people with issues spell out their circumstances rather than the more frequent approach that goes something like "My fish are dying.  What am I doing wrong."

 

Let me take a while to digest your post.....and to do your efforts justice.....and I'll be back.

 

Gary

 

Hi FishE,

 

Sorry 'bout disappearing on you like that but I've been dealing with a severe case of computer-induced psychosis.

 

It seems as though you've been in good hands anyway......thanks Ravnis.

 

Okay Ravnis thanks again for the insights.  I have started today dosing some potassium bicarbonate into the water to try and get the KH level up.

 

I "solved" my DO problem today.    Seems that last time I changed the membrane on the DO meter probe, I must have slightly pinched the o-ring that seals the electrolytic solution within the membrane.......I guess as the solution got more and more contaminated with tank water, it threw the readings more and more off (and more and more variable).    Although I feel like an idiot for not discovering this issue sooner, I can't even begin to put into words what a relief it was to discover that.

 

Now, I'm still not into the 6-7-8ppm range, but at least more comfortable in the high 4's to mid 5's.    Are there any other methods of increasing DO to get it higher (besides decreasing water temps)?

 

And finally, what should I be looking at / considering to solve the "lots of plant growth but lack of fruiting" issue?

 

You guys are great, I really appreciate your help.

 

My limited experience of digital water-testing instruments suggests that, whenever I get a contrary reading of any type, to suspect a meter malfunction of some kind in the first instance.

 

Gary

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Sorry 'bout disappearing on you like that

 

Hi Gary, no worries mate!    Sounds like you had "bigger fish to fry", hope it all worked out.

 

And yes, for most critical measurements I like to have two different types of instruments to double-check against each other in case of suspicions, but with DO I just have the one meter, have not wanted to spend the $$ to buy another (but will eventually).

 

So now with my corrected meter and additional air pump and stones, I am comfortably in the mid 4's to mid 5's at water temps of 78-80F........much better-er.     Now, how does one reach the 6-8ppm DO Nirvana range that I am supposed to shoot for?     Any idea at what water temps this "ideal" DO level is supposed to be achieved at?

 

Ravnis, I have started dosing with KHCO3 (= potassium bicarbonate for everyone else!), it doesn't seem to do much for moving the pH (same results I get when using calcium carbonate ---- not much pH movement).     Am I dosing too low or ???   I've been using about a teaspoon of chemical per dose  (once a day).

 

The hydroxides have me spoiled, I guess, as 1 teaspoon of calcium or pot hydroxide really moves the pH meter.......

Edited by fishE (see edit history)

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Not looking for ph movement as much as KH change.    I wound up using 1/2 pound to  a similar sized system.  Of course that much at one time would kill the fish with ph shock.  So , I used the vinegar to help me get the ph down while raising the KH.

 

So when you add it, measure ph to make sure it's not jumping too high. Monitor KH and strive for a level about 80 ppm.  Then work on ph.

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Hi Ravnis, thanks again for the insights,   I try to be conservative in my dosing regime (mainly because I don't know what I'm doing yet!) so I will take your advice to heart.   Guess I better order some more bicarb as I sure don't have that much on hand.

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Would also like to ask for feedback on a discussion I had with another individual regarding the lack of plant fruiting:

 

ME:  I can't understand it.

 

THEY:  You don't have enough fish, there's not enough fish to support those plants.

 

ME:  The plants are growing like all get-out, what nutrients are missing that's causing these problems?

 

THEY:  You don't have enough fish.

 

ME:  How many fish do I need?

 

THEY:  400 or so.

 

ME:  How would that help?

 

THEY:  You'd get more fertilizer.

 

ME:  But my nitrate levels are already pretty high (160ppm).

 

THEY:  You need more fish.

 

ME:  But if my nitrate levels are 160ppm, what difference does it make whether I have 1 fish or 400 fish?

 

 

 

Thoughts?   Am I missing something?

Edited by fishE (see edit history)

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Ya, you need to talk to someone else...

 

 

 I would also encourage you to look at IAVS system., got to run now, but try to find a link for you later if someone doesn't do it for me.

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Ya, you need to talk to someone else...

 

 

 I would also encourage you to look at IAVS system., got to run now, but try to find a link for you later if someone doesn't do it for me.

 

Hi FishE,

 

Re your conversation......the person to whom you were speaking doesn't understand plant production.  If you have plenty of vegetative growth, but no fruit, your plant nutrient profile is inadequate.

 

You'll find out more about the iAVs.....here.  This system will allow you to grow fruiting plants without any supplementation......and it affords many other benefits, too.

 

Gary

Edited by Gary Donaldson (see edit history)

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Hey Guys, well I thought so (about the "not enough fish" comments) but just wanted to double check with the experts!

 

Gary, what do you think I might be lacking in my nutrient profile?   I posted levels in the original post in this thread, here they are again:

 

 

Nitrates:  has basically always been in the 80-160ppm range ever since the fish grew past the fingerling stage (it’s rather difficult to get more precise readings of nitrates using the API test kit, and 160ppm is the maximum that it goes up to, so for all I know it may be higher).

 

Iron:  supplement with chelated iron, runs 1 - 1.5ppm

 
Magnesium:  supplement with magnesium sulfate and/or dolomitic lime, runs in the 10 - 15 ppm range.

 

Calcium:   supplement as part of the pH control process using dolomitic lime, calcium carbonate, and (mostly) calcium hydroxide.    Runs 20 - 40ppm

 
Potassium:  supplement as part of the pH control process using potassium hydroxide, as well as occasional additions of Kelp Extract and a Humic/Fulvic acid solution (which contains a little bit of potassium).    Potassium ranges anywhere from 40 - 80 ppm.

 

Phosphate:  .25 - .50ppm

 

 

 

BTW, the Potassium levels are expressed by the test meter as either K+ or K2O, what I've reported above the K+ levels (40-80ppm), although I'm not sure what the difference between the two levels are in relation to plant nutrition, and which component people refer to when they say "try to shoot for "X" potassium level".....

 

And as long as we're on this subject, these "recommended" levels seem to vary considerably depending whom one reads or talks to.    These are the guidelines / targets that I've been shooting for:

 

Calcium  40-120 ppm

Iron     2-3 ppm

Magnesium:   20 ppm

Nitrate   20-40 ppm  up to 160 ppm okay

Phosphate:    20-40 ppm

Phosphorus:  20-40 ppm

Potassium  20 ppm

 

Try to keep Magnesium and Calcium levels equal to or LOWER than the Potassium levels:
Mg , Ca =< K

 

NOTE:  too much Potassium will lock-out calcium uptake.

 

 

I know that I've been somewhat severely lacking in my phosphate/phosphorus levels, I've dosed with a bit of Super Triple Phosphate compound throughout the growing cycle.     But again, I'm always hesitant and very conservative in my dosing, as I'd rather under- than over-dose (fish or plants) during this excruciating "year of learning".

 

I bought the (rather expensive and time-consuming to use) chemical element readers because when I first started, everyone just said, basically,  "well, look at the leaves and then look at these pictures/drawings and determine what's lacking and then add some of that chemical(s) and watch for a reaction".     Of course, in the fine print it then says "a nitrogen deficiency can look a whole lot like a magnesium deficiency which also looks like a phosphate deficiency and also make sure you take into account that you could have multiple deficiencies going on at the same time......" and I said to myself, "self, this is absolutely the craziest thing I've ever heard of", so I reached out to some people and they said "well, if you REALLY want to know then you'll need to take multiple plant tissues samples and have then analyzed", so I went down that road and it's $25 per sample and you don't get the answers back for 2 weeks, so.........then my next quest was to try and approach it "scientifically" (i.e. hard data) and that led me to aggregate the above "target ranges" for the most important nutrients and invest in the element readers.

 

As usual, input and feedback is greatly appreciated!

 

 

And yes, I have looked at and read about the iAVs system (both on your website Gary and in other places, including the many comments by Mark on this website), in fact the fellow who steered me into this current system talked about (and somewhat worshipped) Mark M. quite a bit (but never really mentioned the sand growbeds option......).    So that may be a future step in the evolution of my system, but right now I still think that I'm lacking in some fundamental understandings and actions/behaviors and want to tackle those first........like I said, vegetative growth has been pretty exceptional, so I must be doing something right, now I want to chip away at all the other problems and get this system working right........that way, I'll have:  

 

a)  filled the gaps in my knowledge and experience and

b)  have a good basis for comparison in the future.

Edited by fishE (see edit history)

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This might be of some use for you :

 

http://aesl.ces.uga.edu/publications/plant/Nutrient.asp

 

With phosphorus my test kits always max out.  Others have had problems with low phosphorus, but sometimes it was in a different form than the test kit read.   I do recall having to add phosphorus initially, but then it is like a switch was flipped and it went off scale.  If the levels are truly that low, that would be the next thing I addressed after stabilizing ph.

 

Is your KH coming up now?

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I've been dosing a little bit with pot bicarb daily, levels (as measured by the API KH test kit) are up a little bit, but not anywhere that they need to be, will continue adding until adequate results (60-80ppm) are obtained.

 

 Yesterday, to my joy, I discovered that one of my indexing valves "isn't".......it's stuck in one position.    Took it apart, cleaned it, no help.    Installed a new stem/diaphragm and a new indexing cam.    It still isn't.       I wish some made an electrically-controlled indexing valve, the water pumps I use put out God-like amounts of volume but very little pressure.

Edited by fishE (see edit history)

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Isn't that what RupertofOz has......an electronic indexing valve?

 

Hmmmm.........how does one get in touch with such a fine gentleman?

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