1. Don't worry about Alk or CH now.

2. Keep your pH in the 7.2 - 7.4 range, for now.

3. Don't worry about phosphates less they are over 1,000 ppb (1 ppm)

4. Don't use ANY algaecide -- even if you have it -- unless it's polyquat. Polyquat is also a very effective clarifier, so if you want to use an algaecide, that's one more reason why polyquat should be your only choice. www.poolsolutions.com/polyquat.html

5. Check your sand. If the previous owner used Baquacil or similar products, it may be gummed up and need to be changed. Or, if the pump is oversized, a lot of the sand may have been lost during backwashing.