so i have 72 gallon bow front, and have been recently having problems with nitrite and nitrate spikes. so ive figured out that it is my sand bed that is not working properly. too deep of sand for how fine the sand is. so my problem is, is that im buying a new light, metal halide, but all my rock needs to be restacked and the different bigger granuals of sand need to be replaced with the existing fine sand. what type of sand should i use to get that denitrification that we all look for. im also thinking that i should just start all over. i dont have too many coral, so its not a money problem. plus i have cyno bacteria, popping up allo ver the place, sand and rocks. can i clean those rocks somehow. maybe with a toothbrush in a seperate tank? im so confused, someone please help.!!!