Help! Bacterial Bloom in cycled tank

[allcapps]

Struggling to get rid of a cloudy tank. Tank has been established for a year. Here are the parameters:
Bare bottom with river stones
Sponge filter
ph 7.6
ammonia:0
nitrites:0
nitrates:10
temp: 65
no direct light
has a large air stone
no biofilm

About a month ago the tank became super cloudy so I did about a 60% water change and cleaned the filters and decor in tank water. The tank is clean and no matter how often I change the water the bacteria remains. Water parameters look good, no cycle crash is indicated and he is eating fine it just looks terrible.

 

[wolfen]

if it's bacteria bloom increase biological filtration, the bacteria in the filter will out compete the bacteria in the water column for food.
if it's debris ensure good mechanical filtration, debris and calcium carbonate (because axolotls like hard water limescale can sometime cause issues) can give appearance of cloudy water similar to bacteria bloom.
if it's algae bloom, reduce full spectrum light (this is mostly natural sunlight), reduce food amounts,use regular water changes to reduce nutrient levels, add plants.
a damaged cycle can cause bacteria bloom, always dechlorinate water before adding to tank, clean/squeeze/rinse foam/sponge mechanical filtration media in old tank water, clean/rinse biological media in old tank water, replace activated carbon monthly whilst other chemical filtration such as zeolite or ion replacement/exchange resin can be recharged and reused if needed.