I have a 75 gallon tank that has recently finished cycling. My alkilinity level is low and needs to be brought up. It is currently at 7.28 dh. The calcium level has also increased over the past week from 450 to 500. My pH is at 8.1 with the sg @ 1.023 with no ammonia or nitrites and nitrates at close to 5. I am ready to add some clean up crew but want to get the alkalinity and ph up and the calcium down. How do I go about doing this?