Backyard Aquaponics
A place to discuss aquaponics

I had 25 of Gavin's fingerling rainbows added months ago; 2 jumped shortly thereafter leaving 23.

For the last few months, everything has been going well. Two weeks ago, I switched the pump over from continuous pumping to 30/30 on a timer, and at about the same time switched up the feed from "fresh" 3mm pellets to 5mm pellets which had been in the freezer since February; the fish fed enthusiastically.

I've been working heaps and running heaps more, so haven't had the time to interfere with the system, but I noticed on Wednesday the fish weren't really interested in feeding, but were otherwise normal to my eyes. On Friday one fish (155g) was floating. Today (Saturday) I noticed another fish upside down on the bottom of the tank; not dead but not healthy, swimming head down and having difficulty maintaining normal buoyancy. Thinking swim bladder infection, I removed the sick fish to a shallow quarantine tank with heaps more air and some added salt 3ppt, 4 hours later it died (151g) along with a runt in the main tank (95g) which wasn't previously exhibiting any signs.

A necropsy on the two recently deceased did not show any abnormalities; no lesions, no discolourations, good slime coating, no fin rot/damage, pink gills, good innards, clear eyes, digesting food in the gut, their swim bladders looked normal insofar as I can tell.

I've switched back to CF, added another pump for circulation and aeration (in addition to the 2400lph pump through 2x10cm airdiscs, running continuously). The tank is 1000L with about 650L of water so I've topped up with another 150L of water straight from the tap. I've added some more salt to the 1ppt that was.

Water:-
Temp: 16C
pH: 7.0 (digital)
Ammonia: trace < 0.25
Nitrites: 0
Nitrates: 30
Salinity: 2ppt (approx)

Every now and then, a fish may just die, but to have three die in 24 hours with no apparent cause is troubling, especially when the third died so suddenly; there has to be a reason and I must find that reason before the remaining 20 follow. If it's not the water and not the feed, there's been no contamination that I know of... what else is feasible to check?

Anyone got any other ideas? I'm stumped...

Ive lost all mine except 1 now. Still cant figure it out mate. The first few had roots in the gut cavity but the rest have just been falling over for no reason I can find. These guys are in the same FT as the silvers and none of the silvers have died.

You too??!!

I've lost 3 from 12

Monsanto

Seriously guys what is going on over there with trout deaths

Knocking on wood (head) furiously here

Hey Bunson,

Sorry mate I cant remember what you were talking about,

but that chic dancing in the leapard print skirt and black top is pretty hot

Woops just watched the vidio again there is no little Leapard skin skirt, my imagination must have added it

I've had one go, last week came out in the morning and he was floating all were fine the night before and all ate normally after i scooped him out, i tested the water after and found my ph was at 5.5 that was the only thing out though, autopsy looked healthy too

I have been hit with low pH which I cannot get back up (using eco rose and shell grit). Caused an ammonium spike which took out 4 silvers but non of the trout. The trout are now very hungry due to low feed rate as I try to get the pH up, ammonia down and the bacteria active again. Check your pH meter.

pH meter is regularly calibrated... pH is 7.0 (which is a little higher than my usual 6.5-6.8, but I did add about 150L water pH7.2, so a small increase in pH is not unexpected). pH is not the issue in my system.

UPDATE: all remaining 20 fish still alive. They took a small feed yesterday but are not at all interested in feeding today. Will see what tomorrow brings.

Got my fingers crossed for ya mate

Bunson, I take it you have used frozen fish pellets on previous occasions without any issues? I lost a few Rainbows a day after I changed from 2.3mm pellets up to the 5mm Skrettings product, but I assume it was because I fed them more on change-over day than my filtration can handle. It makes it more difficult to narrow down the cause of your problem since you effected a few changes simultaneously. Maybe the flood and drain cycle briefly stirred up some toxin or other? Good luck with the rest, anyway.

Blind freddie, leopard skin skirt is really there, from 0:46-0:49secs!

Hi Bunson, I Hope your remaining fish are OK, any further updates






Thanks PLJ I'm glad some one else saw her too

What about the hotness on a scale of 1- 10

I realise this in unlikely, but here in Adelaide there is a very common bush that turns out is very poisonous to fish. EB noticed it just in time before I gave up on aquaponics.

It looks like this...



I had this plant overhanging my fishtank and I had fish deaths two or three days after each time it rained.

Other things I looked at included checking upwind for new smokestacks, or for people spraying roundup or similar. I think it was Rup that lost a lot of fish when someone used roundup nearby. Also make sure there isnt some non-plant based toxin that rain is rinsing into your system. I recall someone had a tar sealed carport ceiling or similar, that was causing fish deaths when it rained.

Ive got a sneaky suspicion my neighbour was spraying his fence perimeter around the time I lost mine. Whats strange is only the trout died. Although, SP are fairly bullet proof.