Hi Pinkangel,
Just a note that any amount of ammonia and nitrite, even seemingly minute, can cause toxicity/chemical trauma to more susceptible axies.
Nitrates although more benign, if still allowed to build up over 60ppm, especially around the 80ppm mark, can also negatively affect your axie as well as cause other problems like algae blooms.
The only way to keep these in check are regular water testing and 20% water changes as well as siphoning up detritus and uneaten food.
Axies can tolerate a range of pH from around 6.5 - 8. Therefore pH itself is not as critical compared to ammonia or nitrites although ideally you want a neutral pH around 7. At higher pH, more unionised form of ammonia becomes available and this is actually the more toxic form. So when you have high pH, it is even more important to make sure you have 0 ammonia and nitrites.
Cheers.