fish killer mystery

[johnstatron]

I have a 90 litre tank, currently stocking 1 angel fish, 1 pearl gourami, 4 silvertip tetras, 5 corydoras, 1 siamese algae eater and 2 bristlenose plecos. About 3 weeks ago i purchased 6 cardinal tetras. They settled in fantastically and thrived for the first 2 weeks. Then all if a sudden i wake up and see one of them was extremely beat up. Next day all 6 were dead. I originally thought it was a dodgy batch. the fish store very kindly reserved another batch for me and recommended me to stick 2 more in and watch the fish. Everything seemed ok until today where i got home from work to see 1 of the 2 tetras dead and looking damaged. The angelfish fins also seem damaged and 2 of the 4 silvertips (females) look damaged. Seems like a fish killer is on the loose. Any suggestions?

 

[xxEMOxLIZZARDxx]

I'll add my two cents, but I think you need more corydoas and more tetras as they are both schooling fish.

If anyone else has something add I'd go with what they say first.

Also, water parameters are also helpful.

 

[jaylach]

As a start the tank MAY be over stocked, too many fish for the water volume.

 

[GaryE]

Silver tips are really cute fish, but they have an earned reputation as fin nippers. They get bored easily. I had a wonderful group years ago, but in time, I had to give them their own tank. They liked the soft tissue between fin rays.

I expect at 2 weeks, the cardinals died from something they carried. I think I said that in one of your other threads - if I didn't I meant to! The first 3 weeks are quarantine time, and that's when the ugly surprises happen.

 

[AdoraBelle Dearheart]

90L is only 24 US gallons.

You're both overstocked in terms of number of species in too small a tank that they will soon outgrow and become stunted if not upgraded in time, and you're got them in the wrong numbers. That's always going to lead to trouble sooner or later.

My advice is to increasing water changes massively- what's your schedule for W/C's now, and how much water do you change at a time? Poor water quality will lead to poor health and stressed fish, which could increase irritation and aggression.

You're mixing fish known to nip or aggress, and they do so even more if not kept in the right numbers.

Increase water changes/tank cleaning, then I'd recommend reading the species profile on Seriously Fish, for each species you keep. Make a note of the minimum size tank each species needs, and you need a tank large enough for them all at adult size, including the angel. It'll be a choice between getting a much larger tank that can house all of the species you listed, or whether you can return or rehome any of the fish that can't spend their lifetime in a 24g. Also a decision about whether the species you have can live together peacefully.