kH and Alk to high. Phosphate question as well

[cvrle1]

I just did a test for my alkalinity and kH and numbers I got are too high. How can I lower them to regular parameters?

This is what I got: kH is 9.6dKh
Alk is 3.462 meq/L

Rest of parameters are:
pH 8.4
nitrate 0
nitrite 0
Calcium 400
ammonia 0

I have phosorb pouch and I add calcium every 2 weeks (Seachem reef complete)

I also tested for phospates and I got a number between 0 and 0.25 (test has 0 than 0.25 range), I tested my top-off water and it was 0. Where could phosphate come from. I feed frozen plankton once a day very small portion.

Thanks for the help