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New Aquaponics System - Use of soil medium over hydroton with continuous flow

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Thanks Gary.

I plan on adding a room heater to help the grow light/tank heater make a greater gain over the ambient temps which are now low in the 20's - high in the 40's F. Other than this, I just plan on taking my measurements and waiting this process out.

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03/22/13 Update: 70F, ph 7.4, ammonia 3.0, nitrites 0.25, nitrates 0

The earthan bed is working out quite nicely thus far. I have it planted with peppers, tomatoes, broccoli, eggplant, cucumber, lettuce, carrots, beets, beans, basil and cilantro (onions coming soon). I set the garden up with a SFG layout, although I have not added the characteristic grid yet.

I didn't have to wait for the system to cycle and have fish since the soil mixture has enough nutrients to support the plants. The bed is mulched with newspaper and the soil seems to be evenly moist, but not soggy. I have probably added about 5 gallons of water to the ~200 gallon system over the last 10 days.

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Very nice Gary, and I am quoted, hot dang! My system is mostly modeled after Paul's earthan bed write-up, and I must continually give him credit.

It does seem that many of us are constantly tweaking various systems, putting our own spin on things, and trying to integrate the various backyard growing efforts. It is amazing to have so many folks freely share the results of their efforts, and collaborate online. IMO, probably the best thing that the internet has to offer.

Anyway, here's another update on my system:

03/25/13: Day 14, 72F, ph 7.4, ammonia 3.0, nitrites 5.0, nitrates 3.0

It seems that as Paul noted, the bacteria in the soil medium really does jump start the system quickly. Tomatoes and eggplant are growing nicely, and most seeds have sprouted. Peppers are coming along a little slower, and the broccoli doesn't seem to be growing as quiclkly (probably too warm for the broccoli and may have to switch this to a summer variety).

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Hi Ed,

Very nice Gary, and I am quoted, hot dang!

Thank you.....and credit is due to you for helping me make some essential connections in my thinking.

My system is mostly modeled after Paul's earthan bed write-up, and I must continually give him credit.

And that's entirely appropriate.....given that his system is where you first looked in detail at integrating soil-based systems.

It does seem that many of us are constantly tweaking various systems, putting our own spin on things, and trying to integrate the various backyard growing efforts. It is amazing to have so many folks freely share the results of their efforts, and collaborate online. IMO, probably the best thing that the internet has to offer.

It's the constant "tweaking" that produces the incremental improvements in the way we do things. Having said that, we all tend to spend a fair bit of time re-discovering the wheel to some extent.

For example, we owe credit to the wastewater treatment industry for most of the filtration strategies that we use in aquaculture.

Less well understood is that constructed wetlands that were pioneered in wastewater treatment (back in the 1950's) are the precursors of the humble grow bed.

Of particular interest, is the fact that constructed wetlands come in various configurations including:

  • Surface continuous flow - like a grid-watered media grow bed.
  • Sub-surface continuous flow - like a subsurface continuous flow media grow bed.
  • Tidal - these work exactly like a flood and drain media grow bed.

......and some of them are totally filled with gravel.....and others have soil/sand over gravel.

What we describe as raft tanks have long been used to remove pollutants from water - using aquatic plants like water hyacinth and duckweed.

Regardless of their origins, they are shaping up to be the "Ultimate" grow bed.:wink:

Gary

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Hi Ed,

When I listed the various types of constructed wetlands, I omitted (lest anyone think that the wastewater industry hadn't covered the whole aquaponics ball game) the "hybrid" system......a combination of sub-surface systems and ponds filled with aquatic plants.

Gary

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I figured that some pictures are overdue, so here are a couple. The system is running on the earthan bed only, and there are no fish in it yet, but we are getting close:

03/27/13: Day 16, 70F, ph 7.4, ammonia 2.0, nitrites 5.0+ (off chart), nitrates 15

post-8141-13795791190744_thumb.jpg

post-8141-13795791190043_thumb.jpg

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Thanks Ravnis.

One question I have is regarding the transition between cycling and adding fish. I believe that I am supposed to wait until ammonia is zero before adding fish, but if the lag between zero ammonia and fish is too long, wont this start to starve the bacterial colony?

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Hi Ed,

One question I have is regarding the transition between cycling and adding fish. I believe that I am supposed to wait until ammonia is zero before adding fish, but if the lag between zero ammonia and fish is too long, wont this start to starve the bacterial colony?

At the point of cycling, the ammonia and nitrite levels drop to zero....but that doesn't mean that there is none of either in your system. It simply means that nitrification is converting the ammonia (as it occurs) into nitrite....and subsequently into nitrate.

Once cycling happens, you continue to add small quantities of whatever ammonia source you're using until you add the fish.

Gary

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I have had to add ammonia about every other day because it is being converted very quickly. Nitrites are still high, 5.0+ (off scale), and nitrates are ranging in the 15-30 ppm. Temperature has been steady at about 70F, and pH is starting to drop and is now at 7.2.

I guess I just have to wait for nitrites to drop and then I can add fish.

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Hi Ed,

You're going well......just ease back on the ammonia and allow the nitrites to settle back to around 3 0r 4......then maintain things at that and it will happen.

Ignore the nitrate readings at this stage.....they are probably false indications anyway.

Gary

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Thanks Gary. I have added ammonia because it had dropped to trace amounts, but will ease up as you suggest. Putting the hydroton bed into the system later today and adding some plants - exciting stuff. I'll post some pics.

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Ed,

You should still add ammonia after the system cycles (up to the point where you add your fish) but your nitrite levels are a bit too high......to the point where they could overpower the bacteria that convert the ammonia to nitrite......so we just need to throttle back until the nitrite drops to zero.

Gary

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So, looks like my system is cycled, with ammonia and nitrites near zero, and nitrates in the 15-30 range. Fish are coming next week because of coordination with time off from work. In the meanwhile, here are some picture updates:

post-8141-13795791273362_thumb.jpg

Radial flow filter and biofilter/sump.

post-8141-13795791271254_thumb.jpg

Earthan bed, hydroton bed, whole system.

post-8141-13795791271927_thumb.jpg

post-8141-13795791272586_thumb.jpg

post-8141-13795791274102_thumb.jpg

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Thanks Gary. I'm psyched that it's come together well and am looking forward to adding the fish.

My only concern is my power consumption. I may have to eventually go with a greenhouse to avoid running lights year-round, but not sure that I'd be better off with the requisite heating in the cold months unless I undertake some major project taking advantage of ground temps, heat sinks and such.

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I'm using a 600W dual arc bulb on a light mover. It does help with temps; while temps outside were dropping into the mid 20's overnight with highs in the upper 30's, the room maintained at close to 50-60 between the light and tank heater. I have some serious insulation, and a good amount of thermal mass, so temps do not fluctuate much.

I may have to switch to T5 lighting in the summer, and I'm still considering putting in a couple of tube skylights, but the break even point on that expense seems a bit far out. Also, my 'lighting guy' at the hydroponics store didn't think that I could run the system solely on skylights, even in the summer.

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I'm a bit confused by the latest status of my system and hopefully wiser heads can enlighten me. The system had cycled, with ammonia and nitrites dropping to near zero. I then added small amounts of ammonia every few days when this reading was showing only a trace. This process seemed to be working well until the last two days when readings jumped. Last time that I added ammonia was on the 8th and readings where as expected on the 9th and 10th. Then on the 11th and today ammonia jumped to 2.0 and nitrites spiked to over 5.0 with no new ammonia added. Nitrates are showing at 40 (highest reading to date).

There are no fish in the system or anything new in the last week - same plants since I started and the only changes are that temp is up to 75F now and ph dropped to 7.2. All the plants seem to be doing well except for the tomatoes that are a bit stringy, wilting in sections and a lighter shade of green than they should be. Another odd clue is that there seems to be the same or more water in the system over the last two days, whereas I had needed to top off every few days prior to this recent development. Yet the system is indoors with no auto fill and no roof or other leaks.

The real issue now is that fish are en route (expected Friday) and I thought my system was ready but now seems that something is askew.

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Hi Ed,

You have no fish in the system so there's nothing of value to kill. We just leave things completely alone now until you put the fish in.

Keep the water rercirculating and the ammonia and nitrite levels will settle daily now until Friday......and everything will be cool.

Add a little pure sea salt - equal to 1kg of salt to 1000 litres of water - that will mitigate against the impact of future nitrite spikes and will serve as a tonic for the fish when they arrive.

Make sure your pH is around 7.0 by the time you put them in.....that's probably about where they're going to be coming out of the hatchery.

Gary

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Hi Ed

... and the only changes are that temp is up to 75F now and ph dropped to 7.2.

Did you have a Ph spike since last week ?

You "reported" this Ph level back then

and pH is starting to drop and is now at 7.2.

This is a odd one ?

Another odd clue is that there seems to be the same or more water in the system over the last two days, whereas I had needed to top off every few days prior to this recent development. Yet the system is indoors with no auto fill and no roof or other leaks.
Another odd clue is that there seems to be the same or more water in the system over the last two days, whereas I had needed to top off every few days prior to this recent development. Yet the system is indoors with no auto fill and no roof or other leaks.

Are you sure? did you log/remember wrong (like the Ph level hehe)

The real issue now is that fish are en route (expected Friday) and I thought my system was ready but now seems that something is askew.

I think your fine, if indeed you had a Ph spike, that might explain the TAN readings,

also I would exspect some fluctuations given that the system has yet to mature and stabelize for another 6-12 months.

There are many other bacterias (than N- somonas/bacter), and fungus, at play in your system (soil-bed) doing the "Nitrifying" and "denitrifying" job.

It takes time for them all to "harmonise" and colonise there respective habitats.

All swings in temp C/F light and cemistry Ph etc. will have more impact now, than later

("askew" as you put it) IMO

This quote :

Four Types of Bacteria are important to the Nitrogen Cycle; • One of the most important biological conversions involves the transformation of N2 into a form readily available for plants.

Specialized bacteria that live in soil (Rhizobium).............

quote end.

from here: http://www.americanaquariumproducts.com/nitrogen_cycle.html

Might be of interest ?

I think Ravnis guess was spot on, knok on wood

Nice work. I'd hazard a guess that your about 2 weeks from being fully cycled given you still have ammonia.

Thanks for the continous reports exciting to follow.

Iff you salt like Gary suggests I would do it at once, so the system stabelizes to it's new salinity levell

cheers

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Make sure your pH is around 7.0 by the time you put them in.....that's probably about where they're going to be coming out of the hatchery.

Gary

I think maybe it might be easyer to have a "quarantine tank" with a lower Ph.

Maybe call the hatchery and ask their Ph level.

Then use water from the system adjust the Ph to hatchery level and water temp like in the transport container.

Maybe slightly higer salt level.

Then gradualy exchange "quarantine" water with the system water over X time (deepending on the differense), when the readings are the same in both BOW's time to releese in the system.

If you can throw a air stone in the quarantine tank, even better.

And I would not start feeding, for a week, then slowly pic up on fod.

Try making the change as less stressful as possible so have a plan.

Finaly if you see any signs of stress on any individual keep in quarentine to easy monitor any negativ developements (and it want efect the rest of the badg)

cheers

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