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mhaigh

Help...my fish all died!

49 posts in this topic

My system is based on the Friendly Aquaponics Micro System, with a 275 gallon IBT tank and a growing trough that is 4’ x 16’ with floating rafts. I have photos but I am not sure how to attach to this thread as of yet.

I have had nearly all my fish die over the last two days and I am at a loss for the reason. I maybe "snatching complexity from the jaws of simplicity"....but if so I can't figure it out.

I started up my system 4/9/11 and the fish seemed to be adjusting well to the 275 gallon IBT tank, the biggest issue was no nitrites/nitrates. Note that the IBT tank had stored an food additive and was washed out profusely and left with water in for several days before a final rinse and refill.

I discovered yesterday, Monday 4/25/11, that I had a bunch of dead fish. Between yesterday evening and this morning I had 50 dead channel catfish (6-8â€) & 18 hybrid bluegills (3-4â€). I still have about 6-7 cats still hanging in there but they are not very lively, and I expect that they will be laid in a shallow grave shortly after I get home tonight. Rough total weight when I started out with the fish was about 5 lbs with a approximate total water volume of 600 gallons in the total system. I have a 300 gph pump moving water from the growing trough back to the fish tank and air stones in both the grow beds and fish tank, so looks like plenty of dissolved oxygen is available in the water.

I thought my water tests were pretty much in line, except for the fact that I have never had any trace of nitrites or nitrates. I did use an nitrifying bacteria additive (Aquatic ECO part #239210 Proline Bacteria) about two weeks ago, but I have never seen evidence of nitrites on the test strips. This morning I used all new boxes of test strips just to confirm that something with the testing was out of whack, the tests came back identical to the other strips. Note that I have used all the Aquatic ECO supplied test kits as recommended in the Micro Manual. Here are the results that I have seen nearly every day.

D.O. 5-8 ppm

Ph 7.5

Amm 2–3 ppm (started out at about 1 ppm after a couple of days of fish)

Chlor 0 (city water had gassed off for a week before I added fish)

Nitrites 0

Nitrites 0

Water F 63F – 69F (2†insulation around the tank, trough floor & walls)

After the first 10 days, I put about 125 onion starts in my 2†net pots. I didn’t have any nitrates, but my onions were a bit stressed sitting indoors.....so I figured I would set them in the rafts anyway. Most of the plants are not thriving, maybe 20 look viable.

I have fed the fish about 3 times in 2+ weeks, not more than 100 pellets a time...just to see how they would react. I was holding off on the feeding to keep from getting a big ammonia blast waiting on the nitrites to wake up. Last feeding test was on Saturday 4/23/11.

I have an acre backyard, no evidence of chemical spraying during this period by either neighbor...will call tonight to verify with them.

The fish started looking weird on Sunday, hanging out in a corner, kind of swimming against the tank wall........thought it was strange (some sort of catfish ritual dating, ha-ha). Now I am sure they were dying......but with 5+ ppm of dissolved Oxygen, I didn’t think they were starving for O2.

I figure that I will have to drain the system completely and start over, but if you could give me any direction to figure what/what/where....I hope not to repeat this experiment in frustration.

Ideas, advise, tartar sauce.........all would be appreciated.

Thanks.......mhaigh

Bethany, Ok

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Dang... I'm really sorry about your losses.

Basically, your fish died from ammonia poisoning. At pH 7.5, temp 69F and 3 ppm Ammonia, you are running at toxic levels. Do a 50% water change and get your pH below 7 for now, and you might be able to save the remaining fish if they haven't died already. Your system is not cycled, so you are going to have to perform water changes on a regular basis until you see nitrites and nitrates beginning to appear. Unfortunately, those bacterial additive products give a lot of folks a false sense of security. The bottom line is that until you see nitrite and nitrate levels in your tests, you are not cycled.

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Kellenw is right. you have not cycled yet. Have you add any seaweed extract to the system for the plants ?

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do you have any media in your system? Surface area for bacteria growth will be very limited with just a raft system and will make it take longer to cycle.

Getting your PH to 6.8 or so will help keep the ammonia from being so toxic while the system cycles. If you can expose the tank to sunlight, algae will grow and consume some of the ammonia while your system cycles. While you would not do this long term, it might save the rest of your fish in the interim.

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sorry you lost so many fish.. sounds like the friendly's manual doesn't include any info about the nitrification process, which means you should wait until your system has populated itself with the bacteria needed to convert ammonia to nitrites, then to nitrates.. some ammonia can be taken up directly by some plants (like duckweed), but not enough to help your system

do you have any additional filtration in your system? (not good to pump the solids laden water through your floating raft beds)

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Everybody, thanks for the good experienced answers!

The remaining fish croaked over the past day, which at this point is a good thing. It allows me to start back up from scratch. I now see the wisdom in getting the system started up without exposing fish to the toxic ammonia runaway spike (if it occurs).

In defense of the Friendly manual it does give good instruction on how to get the nitrites established and to make sure your Ammonia numbers don't get past 2-3 ppm, preferably less than 1 ppm. What I think I overlooked is the relationship of pH with Ammonia, and how cooler water temperatures really delay the nitrites from "spawning".

I will get everything back to square one and get my started up "fishless".

QUESTION:

1. Is there a magic water temperature required to get the nitrites going?

Thanks all.......mh

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the only magic is patience!

mid 70's seems to be about right for the bacteria... but it will still take time..

you still didn't mention if you have additional filtration?

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I do not have any additional filtration, the FA Micro system is supposed to be such a low density that addt'l filters are not required.

Here's the specs I have followed (except I only started with ~5 lbs of fish).

64 ft2 raft area / 20 lbs of fish = 0.3 lbs of fish per sq ft raft area.

Total water volume ~ 600 gallons

FA explains that these density levels work great without addt'l filtering, now on their commercial size systems the filtration is required.

Thanks......mh

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doesn't seem right to me, but others with more knowledge will chime in i hope..

next go around, wait until your system is cycling - get it up to 2 or 3 ppm am, when it can process that in a day, then it's ok to add fish as far as the nitrification process.. but i would still suggest that you do at least some solids filtration with a swirl filter, or trickle filter, and pump "clean" water into the raft area

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I'm not familar with their setup, but I would recommend adding a "hang on the back filter" on the tank or any location you could make it work if nothing else. Keiths suggestions are valid, but you need to increase nitrification. Your rafts will do this eventually without a change, it will just take about a month or 2 longer.

THis would provide 2 things:

Mechanical filtration or solids filtration,

More nitrification surface area.

I've used 2 of the 30-60 gallon filters to handle ~ 100 lbs of fish, but had gravel grow beds too in the system.

Your oxygen levels are good, so it appears the missing elements are surface area and time. Sorry for your loss, but don't feel alone several have made this same mistake when starting(myself included)

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Hi MH,

I do not have any additional filtration, the FA Micro system is supposed to be such a low density that addt'l filters are not required.

Let's remember that the Friendly system runs tilapia and you can do things with them that you'd never get away with any other species.

I think the earlier suggestions about putting a small bio-filter on the system are sound. For optimum performance, I'd also add a mechanical filter of some type.

Gary

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GaryD,

Tilapia is where I am heading, unfortunately springtime in Okla has some pretty wild temp swings (although my water temp stayed between 63-69F), so I was hesitant to start with Tilapia in case my water temps dropped down into the 50's. I will DEFINITELY startup my system fishless next time.

Can you point a beginner towards bio-filter / mechanical filters?

Anybody out there have some channel catfish experience in a AP system?

Thanks for all the advise.......mh

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MH,

I am very curious about the Channel Cats also, I am very new here and have a lot to learn for sure. I am in Northern California and we too have some wild temp swings.

will be watching this thread for sure

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What do you guys want to know? I have quite a bit of experience with raising channel catfish in AP, RAS and earth ponds.

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First one would be, How would they do in a 100g FT in my temps of freezing to 100f. Thinking of adding some cooling coils (cycle water underground) to help in the summer and a solar hot water heater for the summer. Trying to size my system now for my 12'x10' greenhouse. Have access to a IBC Tank, but unsure of past contents.

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What do you guys want to know? I have quite a bit of experience with raising channel catfish in AP, RAS and earth ponds.

KellenW,

I had been floating around 1.5- 3.0 ppm ammonia and the CCats seemed to be okay, the nitrites never activated in my system (what temps were between 63-69F for the two weeks). The temp swings were very gradual, I have insulated my IBT tank and 4' x 16' floating raft grow trough with 2" insulation throughout.

1. Is there a practical limit of ammonia ppm that the channel cats can handle?

2. What kind of min - max temp F can the CCats handle, assuming that the D.O. is at least 4ppm or higher?

3. What other things will croak a CCat, I always assumed they were pretty hardy?

Thanks for your help.......mh

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First one would be, How would they do in a 100g FT in my temps of freezing to 100f. Thinking of adding some cooling coils (cycle water underground) to help in the summer and a solar hot water heater for the summer. Trying to size my system now for my 12'x10' greenhouse. Have access to a IBC Tank, but unsure of past contents.

100 gallons is really too small for channel cat. I wouldn't bother with anything less than about 400 or 500 gallons minimum. They'll handle cold temperatures pretty well, but can experience some winter kills, particularly with larger ones. I lose about 30-40 or so 4-6 pounders every winter in my 14 acre pond. I also would lose a few in my RAS over the winter if it was a particularly harsh one. They handle the heat extremely well, but maintaining dissolved oxygen levels can be a bit of a challenge with really warm water.

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KellenW,

I had been floating around 1.5- 3.0 ppm ammonia and the CCats seemed to be okay, the nitrites never activated in my system (what temps were between 63-69F for the two weeks). The temp swings were very gradual, I have insulated my IBT tank and 4' x 16' floating raft grow trough with 2" insulation throughout.

1. Is there a practical limit of ammonia ppm that the channel cats can handle?

2. What kind of min - max temp F can the CCats handle, assuming that the D.O. is at least 4ppm or higher?

3. What other things will croak a CCat, I always assumed they were pretty hardy?

Thanks for your help.......mh

Hi MH,

Perhaps this table will help you. It shows the upper limit combinations from many tests/studies of ph and temp (mainly temp) as they apply to certain concentrations of ammonia and nitrite. It comes from page 54 of Biology and Culture of Channel Catfish by Craig S. Tucker and John A. Hargreaves, which is a fantastic book on the subject of growing Channel Catfish by the way.

post-1005-13795788146598_thumb.jpg

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Thanks Kellenw

May have to go with a couple IBC tanks instead, just may not have enough room to support that amount of growbeds. Thanks for the ref to the book, going to take a look for it.

John

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KellenW,

Thanks for the chart on the Ammonia/Temp levels.

I am going to get started up fishless this time after my minimum water temp stays into the high 60's, hopefully later this week. My system has about 600 gallons of water.

I have heard 50F and I have heard 55F as the low limit were Tilapia will die, what has your experience been. Are the fingerlings more susceptible to cold water kills than the larger Tilapia?

Anybody have any good ideas for a cheap salvage material solar water heater to help with spring water temps?

Thanks all........mh

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KellenW,

Thanks for the chart on the Ammonia/Temp levels.

I am going to get started up fishless this time after my minimum water temp stays into the high 60's, hopefully later this week. My system has about 600 gallons of water.

I have heard 50F and I have heard 55F as the low limit were Tilapia will die, what has your experience been. Are the fingerlings more susceptible to cold water kills than the larger Tilapia?

Hi MH,

45F is the minimum actually for Blue Tilapia, about 50F for our particular strain of White Niles, 55-58F for most Mozambique strains. I would strongly suggest maintaining temps of at least 60F, regardless of strain, during the coldest times of the year. Fingerlings are far more susceptable to kills due to low temperatures. Adults can handle lowers temps much better typically. Best practices consist of growing out juvenile tilapia to at least 2.5-3 inches at 78-84F temps.

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Sorry to hear of your losses and everyone here has already done an awesome job of explaining your losses. All I can do is smile and nod and agree with the 2 week break-in for any biofilter, even with jump start chemicals.

The only info I could add would be the ammonia/pH/temp. table referred to in this thread can be found in SRAC 463: Ammonia in fish ponds. That, and recommend the "bible" Tucker and Boyd's text on Pond Aquaculture Water Quality Management.

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Hi,

The amount of time that it takes to cycle an AP system is dependent upon a variety of factors including the presence of an adequate feedstock (in our case it's ammonia), the absence of light, suitable temperatures/pH and sufficient dissolved oxygen. Event the type of bio-filter will impact the cycling timeframe.

Two weeks is likely to be the shortest time to cycle most systems......in optimum conditions.

Of course, cycling can be accelerated by using large quantities of water from an existing healthy AP system.

Gary

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the absence of light,

Hi Gary,

Can you elaborate a tad further on this please?

As its the first time I've seen/heard it mentioned.

Cheers,

Shane.

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Hi Shane,

Nitrifying bacteria are photosensitive. You can read more about this.....here.

Gary

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