Lost 7 Fish In 10 Days

I've had my 20 tall running since the beginning of October. First time fish owner. Started with 2 black skirt tetras. Then added 2 corys 2 weeks later. Got ick after I added 2 sailfin mollies. Won that battle with only losing 1 cory. Added 4 guppies the week before christmas. We got my daughter a kitten on Thanksgiving. Started losing guppies after 2 days. In total lost all guppies, the last Cory, and both black skirts. Water tested fine. Tank sits next to a desk and we noticed the cat likes to watch them and occasionally bat at the tank. Is it possible the cat stressed them out and that's what killed them off? Don't know what else it could be.

 

tetras need to be in groups of 6 or more. i'm not totally sure about corys but I think they might need to be in groups of 6 too. that coupled with the cat may have been too much and killed your fish.

sorry for your loss

 

Is your tank cycled? Do you condition your water? What temperature is the tank?
It's unlikely that the cat is causing them to die from stress, I have 10 tanks and a cat and the fish seem to be curious about the cat.

 

Tank was cycled before I added the tetras. I use prime with every water change. Temp is 79.

 

The tetras in such a small group can and will attack smaller fish. They get extremely aggressive if there aren't enough of them

 

The tetras in such a small group can and will attack smaller fish. They get extremely aggressive if there aren't enough of them

This is very true. I had a trio of black skirts wipe out my guppies in a 20 gallon tall

Edit to add: Cory's and black skirts both need 6+ of their own kind to thrive properly

 

Hmm. Ok so maybe the black skirts took out the guppies. But why did I lose them and the Cory? Coincidence? Just very frustrating.

 

How did you cycle your tank?

Can you give us specific parameters (pH, ammonia, nitrites, nitrates)?

 

Was the tank properly cycled? Are you familiar with the nitrogen cycle? Do you know how long the dead guppies were in the tank before found? Dead fish can cause an ammonia spike.

 

StartSmart complete and the 2 tetras were used to cycle tank. Put StartSmart in and fish food and waited 3 or 4 days. Then added tetras. I'm pretty regular on checking water parameters. Always check before fish are added and then daily for a week after. After the first guppies died I checked ph-7.2, ammonia-.25, nitrites -0, nitrates-0. We got them out pretty fast and then kept a really close eye on everything.

 

If you have ammonia and no nitrates, you're not cycled.

What is StartSmart? A lot of bottled bacteria don't work, unfortunately.

 

You're not cycled, that's why your fish died. Ammonia and nitrite should be zero with nitrates showing but under 40ppm. I'm no expert on the process but I'll bet anything that's why your fish died. If you create a post on cycling, the fantastic experts here will walk you through the process step by step and help make sure you get it cycled properly this time.

 

Oops. Talking to kids and typing at the same time doesn't work. Nitrates-10

 

Oops. Talking to kids and typing at the same time doesn't work. Nitrates-10

I can relate completely lol. I'm not well versed on cycling but Texasdomer is one of the ones I trust when it comes to advise, so I'd see what they have to say. I'm guessing the ammonia spike after the dead guppy was caused by the dead guppy but again I'm no expert.

 

Yeah just crazy that we lost almost everything. I figured the initial ammonia spike was the cause. The mollies are doing great though so I guess we'll start over.

 

Yeah just crazy that we lost almost everything. I figured the initial ammonia spike was the cause. The mollies are doing great though so I guess we'll start over.

I wouldn't get anymore fish until you find out what the issue is for sure.

 

Are the mollies the only fish in the tank now? Mollies aren't appropriate for a 20 gal tall, so I would rehome them. The males get up to 5" and the females up to 4" (not to mention they'll overrun you with fry if they've mated with a male in the past year). We can help you stock appropriately if you'd like some help!

 

Tetras and cories both need to be in groups of 6 or more of their own kind

Mollies need at least a 29gallon

Make sure your tank is fully cycled before adding anymore fish

I don't think the cat would have stressed them too much if it wasn't constant and there were plenty of hiding places for the fish.

 

Incorrect stocking.. stress causing ick... make sure you take care of the above before adding fish...

Also make sure your bioload isn't too much

 

Your tank isn't cycled. The fish died from ammonia poisoning