Koi Bloated And Black Moor Leaning

[sahmof2]

We have a 20 gal tank with a koi, black moor, and 2 fancy tail goldfish. We have had it for over 6 months. We went away for the weekend (the first weekend of May) and left a weekend feeder in the tank, when we returned our koi was bloated. We have him in the tank until we finish our pond outside. He is about 7 in. or so. I tested the water over the past weeks and the nitrates have been around 40 and I had them down to 20 after several water changes. I just tested them and they are back to 40, nitrites are 0. Ph is between 6.2 and 6.8. There are no decorations in the tank, only gravel. After I had done a few changes the water got cloudy and I was waiting for it to clear up before I did anything else. I fed them peas yesterday and the koi's belly looks like it has gone down some. He was laying on the bottom and when he swims he swims fine and is eating. He was breathing hard yesterday but he seems to be doing better now. I didn't feed them today to see if that would help. We added some more salt and bacteria starter, my hubby thinks that I put a tablet in for dropsy but I am not sure. I know I put one in another tank. We changed the filter. Tonight the black moor has started leaning. We put a bubbler in it tonight to get more air moving around. The fancy tails are leaning every once in a while. What do we do now?

 

[vinylman]

What are the water stats apart from Nitrites?. No need for a feeder; you can leave fish for a good week without food. See if you can rehome your Koi with someone with a larger tank until your pond is finished. A 7'' fish in a 20g is almost guaranteeing trouble.

 

[WILDER]

No way i'm sorry that you can keep that many coldwater fish in a 20 gallons.
Try shelled peas and an epson salt bath.
Going to have to get a bigger tank of 100 gallons or the fish are going to die of ammonia and nitrite poisoning.