Backyard Aquaponics
A place to discuss aquaponics

My greenhouse system: viewtopic.php?p=190253#p190253

Well, when we went out for a long drive three weeks ago I had a feeling this would happen: today the landlord called to say "we have a problem". I assumed she wanted us out (after 19 years) or that all the fish in the greenhouse system (1 pleco, 3 goldfish, 3 catfish, 25 tilapia) were dead, but she said she netted out one dead fish and saw another she couldn't reach. According to her, the water smells fine and is clear and the fish are hungry. Tomorrow my right-hand-man is putting on dive mask and taking a light to explore the cavern and find any other dead fish. I'll also ask him to do a couple chemistry tests, ph, etc. Landlord ran the hose in for an hour today: probably a 15% water change. I'm keeping fingers crossed.

Possibilities:
fish are starving: she said they act very hungry and water is quite clear. (will ask Chris after his swim)
chemical imbalance (maybe, but she says they were acting hungry and she keeps fish)
(ph crash?). We will know tomorrow and add shell as needed.
disease? (but there have been no new introductions, so what cause?)
parasites? (ditto)
bad food? (but I just bought new stuff 4 weeks ago)

Any other ideas? I'm dealing long distance, no photos. What fun! (grinds teeth)

Have them check air pump and water pump. I've noticed that reduced flow can have a profound effect even when the problem isn't immediately apparent. However, I would expect the fish to go off their feed first.

Hopefully it isn't anything major. On occasion a fish will die for no apparent reason and it might not necessarily be a problem that will affect any other fish. Perhaps a congenital disease that just finally kicked em off.

Fingers crossed for ya.

Dang!!!! how unfortunate mate!!!! first - dont grind those teeth, you are going to need them to eat the rest of your fish and produce think we will have to wait for those results... 2 fish dead, others apparently okay...hmmm, suicide ... perhaps they had a hit put out on them... can creatures easily get to your tank(birds, cats, rats)?

Thanks to both of you for the thoughts.

The pump volume should be fine, but I will have Chris check for obstructions. We have no air pump: I have a far understocked system with pump sized for tank, not for stocking levels. What is a good air pump I could order?

I would be surprised at congenital disease hitting two or more fish at once. I have had no deaths among any of the fish until now. There have been no new fish introduced since the last catfish over a year ago.

No critters can get into the tank to injure the fish, although I set the glass lid ajar for easier access by my elderly landlord. While a critter like a rat or racoon could get in, they could not get out. Birds would also be out of luck. On the other hand, perhaps a murder/suicide might be plausible....maybe the tilapia are depressed....

Another possibility: perhaps the goldfish are dying of overweight and attendant complications. They are the first ones I've ever seen that have shoulders. My landlord could not tell me what species was dead, but I'm sure she would have no trouble identifying cats, so it is either goldies or tilapia.

But in true honesty....I do feel for you in that situation.

Nothing worse than not knowing what is killing the fish. I am hopeing the added air is all that is required. Is it warm in your part of the world this time of year ??? I had a few near calls in Oz last summer with the weather warming up and not enough O2 in the system.

J.

Thanks, Jessy. Night temps are about 50degF (10degC), days are 85degF(30degC). The water only fluctuates by about 1degC(2degF) each day. We simply have not gotten our normal summer 100+degF(40degC) days this year. At that temp there is no issue with oxygen, just with slow fish growth and feeding.

Updates: I just heard a few minutes ago that the water is at 70degF (20degC), near saturation on oxygen, a bit high (about .75) ammonia, and nitrites near zero. Chris fished out two more dead ones, making a total of 4 tilapia and 1 goldfish. All live fish looked really healthy (by flashlight. *grin*), dead showed no signs of violence. Mysterious. He will come back for another swim in a few days, just to check.

So, I see no real clues to the mystery. Dang.

PS: ph is holding steady at 7.5, so nothing wrong there.

I hate the unexplained deaths.

The ammonia level is probably just due to the dead fish in the tank.... what caused the deaths in the first place..

Current guess: one fish died (from ????) and polluted the tank, causing the other deaths. Evidence for this would be one fish much more decayed than others, but my landlord has vision trouble, the dead fish have gone into the compost, and we will never know.

Crossing fingers that all will be well.

Could well be Hydrophillia... a couple of dead fish might have spiked your ammonia well beyond your current reading....

Good luck Hydrophilia, it always sucks to be kickin' in the dark not knowing what's happening.
Wishing all the best to you fish!

OK! More news.....

3 more tilapia defunct with no sign of damage.
Possible haze or cloudiness on in eyes of some other tilapia, but this is a very uncertain datum.

Water: no change on temp or ph, 1.25 ammonia, <.25 nitrites, 40 to 80 nitrates

Added 6.5 lbs of salt (I believe I have about 2ppt, so that should bring it to 3ppt).

possibilities:
1) I wonder if I should run water slowly for a few days to give a 100% water change, then add 3ppt salt to the fresh water, but I hate to lose the nutes and water.
2) I also wonder of the irrigation lines (I branched off for an automatic filler before we left) could be leaching anything toxic into the water, but would think it would affect catfish before tilapia.
3) Might a local fish store be able to help, either by testing water or checking dead fish? I doubt they would be better than this crowd here plus the sharp eyes of Chris (who has kept fish and dealt with trouble).

Thoughts and advice are always welcome....

Good news! Chris checked again last night and found 0.5 ammonia, 71degF, no dead fish. I guess he was too eager to get home after a long weekend to bother with nitrite test, but lower ammo and lack of deaths is very promising.

Good to hear...