Backyard Aquaponics
A place to discuss aquaponics

Hi everyone,

probably not the first time this topic was raised, but I'm quite desperate and looking for some help/ guidance.

So to wind back a bit...

I had to relocate my System about 10weeks ago, so I dismantled the whole thing and rebuild it from scratch reusing some of my old parts. The system was up and running (inlcuding 10 Silver Peerch and one big Goldfish) for about 6 weeks no problem at all. Water Quality was ok (as far as I could tell, Amonia etc normal for a young system)

About 2 Weeks ago I bought 15 new Trouts. First two days no issues... then 2 dead Fish. I thought maybe I did not have enough air going in to the system, since I 'only' had one 300l, one 400l and one 200l air pumps running. So I upgraded to one large airpump, 2100l/h. That was last Monday.
I checked the water, and Amonia was around 0.5ppm. PH around 7.4.

Then today, I opend the fish tank and all fish dead!
So checked the Water again, PH around 7.4, Amonia around 0.5ppm, Nitrate and Nitrite around 0ppm.

Any ideas.... I'm little frustrated since I just lost about $150 in fish.

Bastian

Well I'd say that air is certainly not the problem, that's a lot going in..
Deaths shortly after adding other fish into the system happens quite a bit. I would be guessing it's either diseased new fish or contamination, neighbours spraying etc...

Sorry about your fish Bastion. Is that black tub the fishtank ? How many litres is it ?

What sort of water temperature range are you seeing from 7am to 5pm on a sunny day? Too large a range can kill fish, and if that small black tub is the FT, I would think it could be quite large.

The black box is not the fish tank. The Fish Tank is behind the timber cladding below, IBC container. Its about 750-850l. Water temp wise I'd say its pretty stable due to the amount of water in the system. I estimate the total amount of water is around 1000-1200l.

I don't think the neighbors were spraying anything, since they have a tiny paved courtyard with no plants. And the fishtank is usually covered with a lid.

Hi Bastian,

Sorry to hear about the fish. It sounds like an environmental problem because I would expect deaths from most diseases to be spread out more. Toxins (metals or plants are common), temperature swings, aeration, ammonia. Any rainfall with runoff from the roof going into the system? Any power outages overnight (did any clocks need resetting) or tripped circuit breakers that might cause the Oxygen levels to drop (perhaps it's on a circuit with something else that overloaded and was reset without your even knowing the air was off)? It's unlikely but ... little kids that might have kicked something loose and plugged it back later so they didn't get in trouble?

I'd also think about what has changed in the system and it's surroundings between the earlier setup and this one.

Hope this helps

Tough one...so many variables. Whenever I've lost fish after transport, it's been several days later. A few already mentioned items. Temp swings, any type of air pump issues, run off from roof? I see a down spout in area. This is a tough one. Sorry about your fish.

Wild fish can bring deseases to a sistem if you not take care, but if you bought them and survive for two weeks it´s clear that this isn´t the problem (they have to take a lot of care with that).
Now you should made some water exchange, to made that whatever that is killing the fish just disolve a bit more.
As you have no more fish in your sistem you could try with some sacrificial fish (like the goldfish), cause they are cheaper and you can see if the problem remains.
Also, even with a large water volume if you are having problems you should measure temp, pH, amonia,... daily, to mantain at least your plants healthy. About pH, as it is in the lower measure of the high range you maybe should also check it with the other solution (it helps to accurate it)
Anything else, I hope you can solve it.

Regards

Ok, what size pump are you running, is it turning over 1000 litres per hour or more ? was it pumping all the waste, uneaten food etc out of the tank ?

The pump is circulating about 2000l per hour in its current arrangement. However only a third of this is actually pumped into the fish tank... so that means around 660l.

Having said this, my sump tank is a little bit dirty with some mud from the pea gravel. Not sure if this has something to do with it. In terms of uneaten food, there was some at the bottom of the tank, but not too much... I don't know if this might have something to do with it.

Currently hesitating to buy another batch of fish...

I think I'd clean the tank out and put some bait fish in to see how it goes. If they do OK then look into getting some additional trout. They can just eat the bait fish as part of their food. If the baitfish die then you've still got a problem. Trout are a bit pickier about water quality than most fish so it's not a perfect solution but probably about the best you can do. I don't know what the window is for getting your trout so this might play into your decision as well.

Hi Kilgore,
when you say all fish were dead, is that the perch and goldfish as well or did just the trout die.?
you also mentioned you relocated, is the water coming from the same place as before.?

If you had SP then added Trout, chances are that will kill the SP, they get very stressed when you add active fish like Trout.

I lost my first lot of SP by doing this, now I have two FT, one for each. Not had an issue since. Trout grow out before xmas, system keeps going until next lot are due. Maybe I stick a couple of gold fish in to help. But otherwise fine.

I think that mixing fish in a artificial environment like AP is tricky and while it may look like some illness chances are just stress.

Unless you can get goldfish cheap, just go and get a small number of SP 3 or 4 inches long, salt the water and have another go.

Make sure you clean out any crap from your sump. You can now buy suction thingy's from the Cheidy's Shop, you just connect your hose and suck out all the crap, then the water can go on your garden somewhere.

SP like the pH you are running, all else looks fine.

Good Luck.