Help - Cory's keep dying

[Tessa92]

I run airstones 24/7 in all four of my tanks. Two of the tanks have powerheads as well as lots of filtration. As I understand it (and I'm not expert), increasing flow and surface agitation can help with oxygenation and prevent pockets of bad stuff building up by keeping water moving throughout the tank, even in the awkward corners. Quite frankly, there's a lot of complicated science around oxygenating fish tanks, which I found baffling. But the verdict amongst people breeding Hypancistrus species of pleco, which demand highly oxygenated water, seemed be either run a powerful HOB filter, an HMF filter, and/or powerheads.

Obviously not all fish can cope with powerheads, but tetras should be okay.

I have read that sand should not be deeper than 2". I think that's the rough number. If it's too deep, anaerobic pockets can form under the substrate.

I'll definitely look into buying a powerhead, wouldn't hurt to have some extra flow. Thank you for the advice.

The sand is no more than 2" deep but I think has still developed some anaerobic pockets. Not sure what to do about them

 

[Gypsum]

I don't know how to fix anaerobic pockets that might be festering under the sand. Try Googling. It will turn up answers from this and other forums. I've found that if you can't get a useful or direct answer by asking a question yourself, Google will find someone on some forum in the wilds of the internet who has asked it before.

I'm running a Hydor Koralia 3200 in my 240L tank. My 125L has an overcomplicated mess of three small powerheads -- a Hydor Koralia 900, an Eheim 1212 powerhead, and something almost identical to the Koralia that I bought at the LFS, but can't remember what it's called. Probably wouldn't have done that if there had been better planning, but it does the job. You will find that powerheads range from super cheap to hundreds of pounds/dollars/whatever currency. Hydor seemed to get lots of positive reviews without costing three figures.

 

[Fishiemang]

It's the bloodworms.

I had this.problem a lot. The bloodworms are what is killing your corys. I'd bet money on it.

Get some good quality sinking shrimp pellets, and use mysis shrimp or something. Corys don't do well eating.bloodworms. They get stuck in their intestinal tracts and they swell up (like dropsy) and then die. Seen it with many corys over the years. Stop the bloodworms. Don't feed.the tank for a.couple days. They may recoved.

 

[Tessa92]

It's the bloodworms.

I had this.problem a lot. The bloodworms are what is killing your corys. I'd bet money on it.

Get some good quality sinking shrimp pellets, and use mysis shrimp or something. Corys don't do well eating.bloodworms. They get stuck in their intestinal tracts and they swell up (like dropsy) and then die. Seen it with many corys over the years. Stop the bloodworms. Don't feed.the tank for a.couple days. They may recoved.

That's interesting. I've fed them for years and it didn't even cross my mind. I'll definitely stop, hopefully the rest survive. Thanks for the advice

 

[Fishiemang]

I only discovered it, actually via this forum I believe, years back when I kept losing my corys. I also was feeding them frozen bloodworms from petsmart. Lost most of the corys and some of the tetras. Read about some brands of bloodworms are prone to either parasite infection or they get stuck in the digestive tract and kill fish off. Even larger fish sometimes. I stopped feeding them bloodworms.and wouldn't ya know it, I have 5 that I have had for 3 years healthy as can be.