Cloudy tank and white goop

[frootbats]

Hi everyone, I joined this website because I've been having a ton of trouble with my tank recently. My axie, Chimi, is about 9 months old. We just moved houses and hes never had tank problems until when we moved (about a month ago)
Hes got a 20 gallon tank with sand substrate, artificial plants and caves. The filter is in good condition. I live in arizona so getting his tank cool is a struggle, but I have an aquarium fan that keeps it pretty chilly. About two weeks ago, i started noticing some weird, white stringy stuff on his plants. Within a day, it had spread to the other decorations. I tested the tank and found that it had somewhat higher ammonia levels than whats recommended (but nothing too high). I took the decor out of the tank, but the white stuff detached really easily and got into the water, so i had to completely replace the water. I rinsed off everything really good, including the filter. The water was very cloudy back then. For a week after i changed the water, i kept close tabs on the quality, and the ammonia levels stayed down, and the tank was crystal clear. Now, its cloudy again, and last night i noticed the white stuff was back! Any ideas on what this white stuff is (it wont show up in the pictures i take, but looks kind of like white stringy mucus). How do i get his tank clear again? I changed half the water yesterday and it didnt improve the cloudiness of the tank at all. Should i completely change the water again, or buy some sort of treatment?

[NYC Axolotl]

If it is what I think it is then you need water clearifier. It should clean it up for you. Also get some air pump and some bio sponge filter as a secondary filter too keep your tank water clean .