I have a round 3300 gallon pool and I have a hth 3 way test kit which test chlorine bromine an ph my ph is 7.5 but the other 2 I'm assuming are 0 since there is no color to it when drops are added. Also I haven't added anything to it because I'm unsure of the math or what I need I have shock and I have the big round tablets that go in a skimmer. However I have no idea what to do first please help.