Backyard Aquaponics
A place to discuss aquaponics

I was keeping 4 cat fish in my outdoor pond, since they got to big for the greenhouse tanks. Every day or so we take out 20% of the water to irrigate the dirt gardern because there is not enough room nearby for a large enough grow bed. In winter the fish are feed little and the garden needs less water so the 2 ft. x 8 ft grow bed keeps it clean.. This pond is 2 ft deep and 8 ft in diameter.....about 1000 gal. It is an old galvanized stock tank but it leaked and is lined with pond liner. In addition to the four cat fish it has 12 six in. gold fish and has been in operation for over a year.
Everything was fine untill I brought in 3 water lilly plants and stuck in the water in pots. The water is noticably more clear, less algae and torbidity. In 10 days all four catfish and one goldfish died. I have not changed the feed or water change. The pump has not failed. It has been hot but the lillies give more shade than last year. The other godfish act normal.
The pond where the water lillies came from had two large koi and some minnows.

I was planning to harvest the catfish this fall and move in some of the larger bluegill to reduce overload in the greenhouse tanks. What can be done to keep them safe? Will the water lillies have purged any toxins by then?

Wow, what a bummer. I do know that catfish can be very sensitive to skin irritating toxins but I'm supprised that water lillies that came out of another fish pond would have killed them so quickly. I'm not sure what to tell you. The only catfish I ever had die, were showing signs of skin infection for quite some time before death. Any idea if there was something in the pots that the catfish might have eaten that would be bad for them? Otherwise, water change and test with a few of the other fish and hope it's better come fall?

My catfish definitely show signs of trouble if I stress them out (trying to net them) and overcrowding or poor water quality will keep them from getting better quickly.

Hopefully the source of the problem presents it's self clearly to you as not knowing sucks.

I had for over two years two goldfish in a 1/2 blue barrel with one water lily,
surviving only on algae and mosquito larva with no ill effect and they were growing.
Newer had a water change except for a top up if needed.

But your cats may be a different kettle of fish

Last Sunday saw David Attenborough's The Great Flood

Between the floods catfish were surviving heaped up in a mud pool with some being picked up
by the birds or jackals. Very impressive. Different cat fish, adapted to local conditions.

I would bet there were some kind of hitch hikers in the water lillies. probably bacterial. But channel catfish can be as TCLinx described extremely sensitive to stress. Its like they get nervous hives that leave them vunerable to disease. I purchased 50 this spring and put 25 in the 55 gallon barrel ponics system and 25 in the living room 55 gallon aquarium. I'm down to 9 of the least nervous of the bunch in the aquarium. You couldn't even walk in front them because they would almost panic. The ones that did were the first to go. I haven't lost any in the barrel where the only time they see me is feeding time and thats only if they are looking up. I think they need pretty good water quality, and not nessasarily clear. Can't even do partial water changes in the aquarium without stressing the fish. Now that I'm thinking about it prolly going to put rest of the cats outside.