You can pretty much ignore the TDS readings, too--pool stores scare people into buying stuff in lots of ways, and that's one of them. Looks like the algaecide may be your ammonia source--doesn't it seem odd that they wanted you to add an algaecide to an already chlorinated pool, which degrades your chlorine, and makes you have to add lots more chlorine to counteract the algaecide? Pool store profits.......

Anyway, the best algaecide you can use is chlorine. Skip the other stuff and just be diligent about testing your water. '