Backyard Aquaponics
A place to discuss aquaponics

I doubt rotting material would be the cause. Some of the small creeks I fish are full of leaf material, enough to make some parts dark tannin coloured. If rotten material was enough to cause death I would reckon there would be a foul smell attached to it, and probably a change in water clarity.

Is it possible your neighbors have sprayed some fruit trees or something?

Re light - trout need some light to surive, but not as much as you would think. I came over and saw your setup a month back and they would have been getting ample light where they are.

I feel for you man. This must be devastating.

Gemmell I use a 12000lph Tornado pump at 165wts and 4500lph Resun at about 65wts and both run fine, I would disagree with brendon as my first system had a full sized very smelly dead marron that caused deaths, I have the same problem as Gemmell now and I think it is caused by dead yabbies and also uneaten food, another disaster in my first system was caused by over feeding marron which spiked the ammonia, last year my trout grew to 700gms with minimal light as blocked most out to stop algae,

Gemmell my count is just less than yours at about 37 and they were floating 2 or 3 at a time every few hours, the ones left seem full of life but still not eating, I think you are onto it with what you have found, I have increased my pump cycle and water appears to be clearing, I did add another GB the other day hence the 2 pumps, I would increase your cycle even to 24 hours full on for a couple of days

Yep cycling 24 hours a day at the moment. Brendan was talking about plant matter; decaying fish/yabbies tend to "mank" up the water a bit more from my experience. I would tend to agree that rotting vegetation should only affect ammonia levels (which all read fine). Where as a rotting marron and fish food has all sorts of bacterial and water quality implications. Something to do with protein I gather.

It could be someone spraying, my system is "outside" (no cover on the growbeds). We've also been installing a deck in the backyard, so there's been cutting of LSOP treated pine and ModWood with power tools. But I reckon I would have changed 100% of the water since we did any cutting with no sign of them stopping. However if some got in the growbeds maybe it's just poisoning any water I put into the system?!

Or maybe my neighbor always uses the ANZAC day long weekend to spray for pests.

Clutching clutching clutching. I'm now at the point where I think I'm just going to fish out the deadies, morning and night, and disturb the fish as little as possible. I've noticed that when I lift the cover they seem to go belly up very quickly, where as there is like 2 or 3 dead from an entire day of letting them be. Could be that I've flushed the actual problem out but I'm too busy changing water, pH salinity levels etc to give them a stable environment to recover in.

Hrrm, this is interesting:



I pulled out all my tomatos when I cleared that bed. The other bed is full of tomato's which are at the end of their lifespan. Could this be related (clutching clutching clutching) to my ANZAC day deaths? I guess toms would finish around the same time every year and I might pull them out around the same time every year.

Well tonight has been the worst it's been. Toll must be sitting at about 60 (for tonight only). I found two stuck down in the shell grit pantyhoes. That wouldn't have helped.

I've now added like 3 times as much air and I'm moving the water with the pump without pumping up to the beds. So I'm just going to have to wait and hope. Salt is already at 3ppt, moved a whole bunch of them into the sump of the old system and set it running all night too.

The crappest thing is that I'm going to Adelaide next week (leaving MOnday). So I've no time!

Well that's it for the trout. Pulled out another 100 or so today. No matter what I did, it just seemed to make it worse.~250 dead fish total.

All I've left now is the 50 or so I threw in the sump of the old system (which also has ~150 silver perch being filtered by but 2 bathtubs - so I'm not too happy about that).

I'm absolutely shattered, and I've still no idea what the problem was and when it'll be safe to put some more fish in. I followed all the rules, change part of the water, salt, cycle, more oxygen. Every day the death toll got larger and larger, culminating in all but 4 dying today.

Shattered.

Oh man...so sorry!

Bummer Gemmel... at one stage you mentioned stuff dripping from your roof... has that still been happening??

Any chance of getting it tested???

P.S... I'll be doing a delivery of trout down that way in 2-4 weeks... think you get things sorted by then?

Ouch..... How many fish did you have in there? was it a bit heavily stocked?

300... in 3000L... I think... so yep... a "bit" overstocked...

What sort of aeration do you have running in the tank Gemmel??

I stocked 300 fingerlings in my 6000L tank... with a 12 outlet 6000L/hr magair pump.... and I reckoned that was a minimum...

I got 300 fingerlings with the intention to give 100 to Alfred Deakin High when their outdoor system came online, and 100 to a lady up north who wants them for her pool.

They were only supposed to be in there temporarily - but stayed a bit long - so yes, I know I was overstocked, but given their size I didn't think they'd be pushing the system (3kg/100L filtration and all that).

Aeration - I have the otto air pump plus the venturi pump return. Then I installed the guppy's aquariums ACO6 blower as well when I thought "more O2". Second to that, I would have thought after the first 150 died that there would then be plenty of air for the rest of 'em i.e. that it had to hit a limit where there WAS enough air for the remaining fish. It didn't seem to happen.

I won't rule out air as being the cause - next time I'm just going to get 'em for myself and bugger everyone else.

AS for the black on the roof - it hasn't been cold enough to do it this year.

The problem is - How do I know the water is "safe" again?

Hey Gemmell,

Sorry for your fish loss

To see what is in your water that is possibly killing fish you need to put a sample through a "gas chromatography-mass spectrometer".

http://en.wikipedia.org/wiki/Gas_chroma ... ectrometry

Any major biochemistry lab (such as at a university or hospital) should have one and they will detect and quantify every single molecule in the water sample, then you just need to go through the list, starting with the high numbers, and do some detective work to figure out which compounds may lead to fish death.

The hard part maybe convincing them to let you put your dirty fish water through their very expensive toy, but you never know your luck.

There's a mass spec at the ANU. Charles Hocart is the manager.

Thats a terrible story Gemmell.

I agree with the other comments, you need to find out what the problem was. Youll probably need to keep a fish or two for analysis too to see if it was a disease, but given the 50 you put in the other system survived...you can probably rule that out.

The ANU were going to do some high performance liquid chromatography for me before, so you might be in luck. Id definately give them a ring today.

sorry you lost so many Gemmell, I think mine to are finished, it is upsetting but the worse thing is not knowing what the cause is and will it be safe to add more, hope you find the problem and if I come up with something I will fill you in