heeeeelp! fish keep dying

[FDemon]

Hey guys. Not new to fishkeeping by any means, but I have never had this happen.

I bought a 30gal tank used. It used to be saltwater. The plan was to use feeders to cycle the tank.

I cleaned it with tap water and a scrub pad (no soap), also cleaned the built-in filter and the media. Used pool filter sand for substrate, rinsed it well, there is little to no suspended dust. Filled with tap water and used "stress coat" to condition the water. Water was tested at LFS and they said it was fine. Temps are in mid 70s to mid 80s.

I've so far gotten two batches of 10 goldfish feeders from different LFSs and both batches have croaked. In between the first dead batch and the second batch I did a ~30% water change. The second batch seemed(can't be sure) to be OK for slightly longer.

Here's the thing. The feeders each time lasted about 24-36 hours. When initially going in the water they are completely fine, they eat, swim around, etc.

After about 20 hrs or so they start to go aggro. Lots of them seeming twitchy and zooming around the tank, generally acting crazy. Then they start to go belly up and doing barrel rolls while swimming around, eventually dying. No visible physical problems at all.

It seems like the tank is contaminated... that's my only guess.

Does anyone have any insight? What should I do?

 

[PayaraMan]

Hmmm I've done the exact same thing with my 55 when I moved and everything was fine... If the fish seemed to do better after you did a WC then my only suggestion would be just to drain as much water as you can and fill it back up with the garden hose, Then just condition the water again and see what happens.

 

[PayaraMan]

Then again feeder fish always have something wrong with them... They are bred in the most crowded tanks and carry a large variety of diseases. I bought 20 feeder fish for my payara to eat and I would quarantine them for a week and about 10 of them would die in the best of conditions. So it might not be your water instead it might be the fish.

 

[FDemon]

these feeders all seemed pretty healthy from my experience

also from different shops...

 

[Sab_Fan]

has this tank ever cycled? it sounds like you're experiencing something like "new tank syndrome" with an un-cycled tank . . .

 

[FDemon]

has this tank ever cycled? it sounds like you're experiencing something like "new tank syndrome" with an un-cycled tank . . .

I've always cycled new tanks with feeder fish and tap water.... is this no good?

Also would an uncycled tank cause the feeders to go ape**** for a while?

 

[PayaraMan]

has this tank ever cycled? it sounds like you're experiencing something like "new tank syndrome" with an un-cycled tank . . .

Lol I can't believe I did not think of that, OP, How long have you had the tank setup since you added the feeders? 7 days is a minimum before you add ANY fish.

 

[manlyfish]

Hey guys. Not new to fishkeeping by any means, but I have never had this happen.

I bought a 30gal tank used. It used to be saltwater. The plan was to use feeders to cycle the tank.

I cleaned it with tap water and a scrub pad (no soap), also cleaned the built-in filter and the media. Used pool filter sand for substrate, rinsed it well, there is little to no suspended dust. Filled with tap water and used "stress coat" to condition the water. Water was tested at LFS and they said it was fine. Temps are in mid 70s to mid 80s.

I've so far gotten two batches of 10 goldfish feeders from different LFSs and both batches have croaked. In between the first dead batch and the second batch I did a ~30% water change. The second batch seemed(can't be sure) to be OK for slightly longer.

Here's the thing. The feeders each time lasted about 24-36 hours. When initially going in the water they are completely fine, they eat, swim around, etc.

After about 20 hrs or so they start to go aggro. Lots of them seeming twitchy and zooming around the tank, generally acting crazy. Then they start to go belly up and doing barrel rolls while swimming around, eventually dying. No visible physical problems at all.

It seems like the tank is contaminated... that's my only guess.

Does anyone have any insight? What should I do?

2 batches of goldfish in a 30gal tank while cycling...no wonder your fish are dieing!

 

[PayaraMan]

I've always cycled new tanks with feeder fish and tap water.... is this no good?

Also would an uncycled tank cause the feeders to go ape**** for a while?

Yeah, You see the water in the tank has not had enough time to completely condition itself hence the water is still a little more than 50% tap water right now and will stress fish out until the point of death, That is your problem my friend, I would give it about a week depending on how long it has been setup and before you add the fish add a tiny tiny more conditioner to the tank.

 

[FDemon]

Sorry guys, I don't get it. How can leaving the water sit in the tank for a week with nothing in it there do any good? (like letting water sit in a bucket)?

I've never had this prob before, but I was living in a different city. Perhaps the water quality here is affecting things.