Backyard Aquaponics
A place to discuss aquaponics

Hi All,
Things are crook around here, I have had the system (BYAP) 2000 L pond 3 grow beds,running for nearly a year, grew out approx 30 trout, and noticed just recently that my goldfish where carking it, losing 3 a day.
We noted that a few of the dead ones had chewed on tails, the fancy frilly goldies were the first to go.
I have got all of the trout out now and in the freezer, none of them died from mysterious causes, just a knife in the gills.
The goldies are still dying We have checked the water chemical composition all is fine there, the water has cleared up since the trout have moved out.
Should be no more stress from bullet train trout
Any idea what is still killing my fish? they are very sluggish on the bottom of the tank, not hungry, and diying, My beutiful babaies are nearly all gone, I am a bit worried to put any thing else in?

Salt to 3ppt... do a half water change. Has anything changed recently?

Were they feeding on the trout feed??

I lost mine in similar circumstances... the trout feed is very high protein... 2-3 times what a normal goldfish feed would be....

They were fine one minute... then dead or dying the next... and nothing saved them...

Thanks guys, yes regular salt doses, a handfull every couple of weeks, dont know what the ppm is but it has been keeping the whitespot away that came in the real cold weather.
And yes feeding them trout feed, not that they could ever beat the trout to it though
Ok will get some flakes in the morning, just got to get them to rise up from the bottom of the tank to eat it?

You put the goldfishes in the same tank as the trout? Probably explains the chewed tail...

Well I think it is still possible to feed them trout feed, but not let them have too much... In other words, do not follow the principle of feed as much as they can take for x minutes...

I have been feeding my goldfishes and koi 50% protein feed for almost a month now.. except I only give them 1-2 pellets each per day...

It's possible that the trout may have been getting to the feed before the goldies anyway...

Leaving them under-nourished... combined with a bit of bullying from the trout... like nipping their tails... they'd eventually be exhausted...

Have seen that happen with some Silver Perch I left in the tank when I put the trout in...

Then, there's also the possibility that you might not have been feeding the trout enough... and they were trying to snack on the goldies...

I think the key here is that the goldies are dieing since the trout were removed, is that correct?

One fear is that the trout feed long term has had a bad effect on internal organs of the goldfish and that is what the fish are suffering and dieing from now. I think this is the condition that Rupe said he had.

However, since the trout have been pulled out or since the goldies started dieing, is anything different? Temperature, aeration, water topping up source?

How old is the feed? Really old feed can go bad and kill fish. If any feed looks moldy, rancid, or bug infested definitely don't feed it to the fish. They generally only recommend keeping fish feed for up to 6 months from the date on the bag.

Check the system for any metals that could be corroding and leaching into the system. I doubt this is the issue since trout are generally very sensitive to metals but doesn't hurt to check. Galvanized metals in contact with AP water can be especially bad for fish as can copper.

Good luck finding an answer to what is killing the fish since I know the mysterious make it worrying to put new fish in later.

Thanks for the feedback, the drama goes on, all original fish now chook food or plant food
Went out to a dam in the bush that has carp type goldies, bought home 6 the first weekend all good for a week, bought home 26 the next (last weekend) back down to 5, more fertiliser.
Stopped feeding the trout food (still appears in good condition and not that old)they get the odd chook pellet or bread crust, which they were caught using.
Salt 4ppm to 3 ppm over two differnt reading a fortnight apart
Pumped out a heap of water and added new - once
Topped the sytsem right up so heaps of H2O
all readings, A No2 No3 Ph etc sweet
no metal in the system all plastic in contact with the water

next step a full water test I suppose?
can anyone advise of a test lab that does this
Cheers all

you have possibly found the problem. I once got some goldfish style carp from a mates dam to use as feeder fish for my cod. I isolated them and they all seemed fine. In the following month of quarantine they all went belly up. Dams and rivers have all sorts of nasties. I would never add those golies style carp to my system. If I were you I would chlorinate the whole lot and start again That means getting a strong chlorinated water thru the growbeds, leasve them full for a day or so then complete flush, dry etc. It sounds drastic, but at least you would kill any nasties.
I would say almost 100% it is not the feed. I feed 45% protein feed to my goldies and shubunkins and have been since we moved here and I rarely lose a fish.

Thanks Monya,
The carp never went in until the originals had all died, I did have some in from the same dam that OBO gave me months ago, and they survived all this time (until the big cull that took out every thing)
I think the mass death was definitly from the trout just being to active and hungry, and stressed out the others? I havce had some really nice clean water that smells good but these next lot of fish are doing my head in a bit
Compared to their previous dam home they should be in heaven

I had a sore head all day Jim

Not my fault OBO, all self inflicted.
still cleaning up the stubbies,
amazing had a fish end up in the yabbie trap with the Marron in it???
Dead of course

Did fish fins look like this:


Because that's finrot not tail attack.

I have had a lot of trouble growing goldfish in my systems, I have this feeling that there is just all too much movement in the water for the lazy bastards.

Cheers Gemmell,
No not that bad, pretty sure the trout where having a nip on their way past and stressing out the fish.
I am pretty much just monitoring what is happening at the moment, I have 3 dam fish left, 5 Marron, and just put in 5 small goldies to take on a canary in a coal mine role before I spend $ on silver perch.
Thanks for your input