Wet drys create bacteria on artificial bio balls, instead of using a wet dry, which artifically does this, and builds up nitrates in the process, you can create what's called a refugium/sump in which you can naturally filter your tank by adding a DSB (deep sand bed), LR, and various macro algaes that you occasionally harvest. This type of biological filtration is much, much better then a wet dry. You can also add the sump section or not based on your taste in which you add equipment in such as your heater, protein skimmer and so on. This type of setup I consider the best way to go, lower maintenance, and gives you higher water quality. Also your 200lbs of crushed coral is also a nitrate buildup spot because all the waste collects within the large pebbles as opposed to a DSB which will remove waste faster because of the extra life it sustains. Anyway just my thoughts, I would never use a wet dry or canister again unless it is for an aggressive tank that needs a lot more mechanical filtration.
