I have owned my above ground 33ft round 54" deep pool for 3 yrs. The 1st yr was great, second pretty good. Now it is terrible. I have been draining it and want to just start from scratch. I have 2" of water left, or should I say algae left. I can't get that last bit of water out. I want to scrub the walls with bleach water. My question is, should I scrub and then fill