Have you cycled your tank? It really helps even though I am currently cycling and its a LOT of work in the beginning but its worth it for him
I am currently doing 50% water changes daily and testing ammonia and nitrites. Once my cycling is over a 10-15% waterchange weekly with gravel vacuuming is all that will be needed
40 gallon - Misc fish
15 gallon - Axolotl
5 gallon - Betta and ADF
20 long - Hatchling turtles and corydoras.
Soon to change I am sure