OatmealWookies

Thank you all for the help! The temperature difference definitely makes sense for my predicament.

Thanks so much for the advice. While I did try to acclimate everything properly, I hadn’t thought that temperature could have played a role in causing these problems when introducing life to the tank. I will slowly lower the temperature and see if that makes a difference. Much appreciated!

Perhaps over a 24 hour period would be sufficient so I don’t “shock” the bacteria when cooling?

Substrate is fine sand. Pool filter sand, thoroughly rinsed prior to use. Half of the sand was from the previous tank, added more upon upgrade. Decor, aside from the live plants, manzanita driftwood, Java moss, and a terracotta pot as a hide. Two pieces of slate as well. While cycling, I try to keep the tank around 78 degrees. I have to cool the tank to at least 68 to introduce them. I cool with the use of desk fans and the a/c and usually maintain a temp between 64-66.

I’ve been fighting this problem for weeks and can’t seem to figure out what I am doing wrong. I have a 55 gallon tank with two axolotls. The tank is an upgrade, a couple of months old, but the sponge filter I seeded it with is well over a year established. Also running a HOB aquaclear 70. I had two sponge filters prior to using the HOB for this tank when I upgraded in January. The second filter I cut up and put in the aquaclear, thereby seeding this tank with two filters. I tested my water as I normally do before my weekly water change and everything was off, except ammonia. Ammonia 0. Nitrite 2ppm and nitrate 80ppm. I took my axolotls out of the tank and put them in fresh daily changed water. Something apparently crashed my cycle. Since this happened, I’ve been dosing my tank to 4ppm ammonia. It went down within 24 hours two different times, for 3 consecutive days. I reduced nitrate down to 10-20 via changing water and introduced them back into the tank, both times. Each time, the following day, nitrite has spiked again. Water changes have not been enough to keep it down long enough to keep them safe. Tested the tank this morning and nitrite was about .5ppm. Tested again 6 hours later and nitrite climbed to 2ppm. Because of the nitrite issue, nitrate is also steadily increasing as it’s getting processed. There is nothing decaying. No life in the tank, aside from some Amazon swords. Plants are doing very well, the tank looks clean and clear, but the water is still toxic. What am I doing wrong? Should I be introducing them separately a couple of weeks apart even if the tank was capable of handling their bioload before this problem? Should I be reducing the nitrates to at least 20, redosing ammonia and then testing again in 24 hours to be certain my cycle is complete before putting them back in? I’m not new to fish keeping or cycling tanks, but this has me exhausted and scratching my head. I’ve tried using TSS twice, and had no success at all. I don’t usually rely on bacteria starters, but tried in this emergency situation. Blunder. Axolotls require cold temperatures so cycling with them in the tank could take an absurd amount of time, and put them in harms way and that’s something I don’t want to do. My cycle keeps convincing me I am done, only to cause an issue the moment I add them back to the tank. Tap parameters are zero across the board. Any advice to figure this thing out would be so helpful!