High Nitrite Levels in My Axolotl Egg Tank

I currently have about 4 dozen eggs that are at about day 9 in development, everything is going great so far but for some reason my tank has continuously high nitrite levels? The Ph will continuously drop down to about 6 but I’ve been using balancer to keep it at a seven. It’s a ten gallon tank with no filter currently so as not to disturb the eggs. I’ve been doing 25% water changes twice a day to help with the nitrite but if anything it’s gone up! I’m honestly at a loss at this point. I’ve been dechlorinating and treating all the new water I put in, but nitrite levels will not go down and I’m worried that once they hatch it will hurt the babies. Any and all help would be amazing. Thanks so much!

In any tank without a filter, especially for babies, 100% water changes will need to be done at least once a day. It is for this reason and the general safety of the babies that it is highly recommended to keep them in in small groups within plastic tubs rather than in tanks. Water chemistry is just not easy to control in a tank without a filter, and keeping them all in a tank without a filter is very dangerous, especially with this problem. I very highly suggest moving them to Rubbermaid tubs to keep them safe. I would also stop using the pH balancer, as chemicals like that are not even close to safe to put in with any axolotls, much less babies. Sometimes chemicals like that can cause spikes in ammonia and nitrite, so maybe that's responsible. Regardless, I would separate them into Rubbermaid tubs as soon as possible. It will need to be done anyways, as that many larvae cannot safely live in that close of a space.