I am U.S. ex Mil and wife is German. The area we live in is Bitburg, renown for its Bitburger Pils Beer. We have a 5550 gal above ground pool. The water table here is hard with high calcium concentration. The biggest problem is controlling algae. Keeping the PH balance with good range 7.2 - 7.4 is very arduous. This year in particular with what seems as endless rain this tasking is particullary more difficult. I have almost 10 kilos of ph reducer added to the water and still the ph is at 7.8 and algae continues to show up. I am grateful for any and all advice.