i have checked the levels randomly and they arent that bad( always in the color range they are supposed to be in) i just always add water(~gallon every 2 weeks maybe) which i think balances it out… but there was only 5 fish in the tank all approx. 1-1.5" long and its a 30 gal tank. now there is 8 fish so once the levels start to climb i think ill attempt to change the water