equitment

Hi I was wondering how much of what chemicals and additives should I use and how often to dose my 90 gallon reef tank. And is there any way to not have to buy dosing pumps.

So I am starting up a 90 gallon tank and would a canister filter work or should I just get a sump.

I'm looking 4 2 k2s and I have 1 k4 forsale 30 dollars or trade