New NeonTetras Dying

[Archman66]

So I set up my tank and let it cycle with 8 1" danios for about 6 weeks. Last Tuesday, NH3 and NHO2 were zero, and NO3 were at 15 ppm, and went to about 20 (15 is between chart colors so I extrapolated). I'm thinking, cool, I'll trade in the danios and get some fish this friday (today). Continued testing, just to make sure, and there was no ammonia, nor nitrites. I do a 25% water change and 10% the following day to get nitrates down for the neons.

So I trade in the danios and get 12 neon tetras (I think they miscounted and only gave me 11).

I acclimated them by placing the closed bag in the tank for 20 mins. Then I open the bad, and pour about a cup (8 oz.) of the aquarium water in. I let the open end hang over the side and repeat after 5 mins or so. I did this four times. Then, I poured the water in the bag through a into a bucket, and released the fish into my tank. So none of the store water got in the tank.

Three died within 10 minutes. So I tested. And sure enough, there were about .25 ppm of Nitrites after 3 days of 0 (yes I'm sure - even if I made a mistake or a misread, I doubt I'd make it 3 times.)

The only thing that changed was that I had to remove some of the plastic plants to net the last danio for the exchange, so the gravel was disturbed some. Other than that, why would I see nitrites again?

Planning on another 25% water change tomorrow. No other Tetras have died, but I'm worried. Any advice, or answers are welcome.

Thanks

[MonkeyPox]

Sounds like you're doing the right thing. If you have some extra Prime lying around, you can overdose and help detoxify the nitrites until your waters gets back into proper spec.

[Archman66]

Read your post and immediately did that. One more died, and one is missing. Hopefully he's just hiding.

[MonkeyPox]

Seachem's site recommends up to 5x normal dosage for a nitrite spike.

You can get a breeder net (or make your own) and section off parts of your tank based on species. This can help identify if one fish is attacking another or there's something else wrong with your water.

Are you adding Prime when you do your water changes?

[mommy1]

dont forget that neon tetras are very sensitive fish, and even putting them into a very seasoned tank with perfect conditions you may lose a few.
your tank is still fairly new to being cycled (6wks) so i think its not unusual that you lost some.
just keep up with what you are doing with the water changes and the prime, and things should even out.

[Archman66]

Only when I'm adding tap to RO water. I top off evaporated water with just RO water without the prime.

[timfee]

In future you may wish to acclimatise your fish more slowly to reduce the stress of the sudden change in water conditions. Add 1/2 cup then wait 10 mins repeat until you've added the same amount of aquarium water as before. Requires a bit more patience but will be better for your fish.

[Archman66]

Status Update.

All but 3 died through the night. I got the dead one's out as soon as I noticed them so they wouldn't contribute to the ammonia load. Nitrite tested at 1.0 ppm (no ammonia), so I did a 30% water change with RO and tap water mixed to a pH of 7.0 (same as tank). Put a ton of Prime in the bucket before adding the water.

I only have 3 fish in the tank, now, and they're neons. My thought is do not add fish until the tank stabilizes. However, without ammonia in sufficient quantities, won't the nitrosomona bacteria die? Is 3 neons enough to keep that bacterial colony going? Or should I add some more hardy fish?

Oh, also got the AC50 filter as suggested in previous post and added to the Penguin 150.

[bushwhacker]

why are you using the ro water? unless your tap is really bad theres no need for it. unless your reconstituting with the minerals and salts your changing your ph and tds every time you do a water change

[Archman66]

why are you using the ro water? unless your tap is really bad theres no need for it. unless your reconstituting with the minerals and salts your changing your ph and tds every time you do a water change

My tap is very soft but high pH (8.2). I was advised to do this in previous posts. I test the aquarium water (it's always 7.0 or 6.9), and I test the RO-Tap mixture and add RO or tap until pH is 7.0. Thus there should be no change in pH.

[Lady Hobbs]

A tank without fish will quickly loose it's cycle without that source of ammonia keeping the bacteria feed.

However, your cycle was not complete or you would not have showed nitrites.

[thrakuarium]

Have you tested your water before adding it to the tank? It seems odd to get such a large nitrite spike without an ammonia spike after running danios in the tank for 6 weeks. You did several water changes and it almost seems the readings got worse each time. I would test your "tank ready" water before you add it and see if you have nitrites in it.