Ok peoples!!! Just got a maxi-jet 600 powerhead and my skimmer is enroute! I purchased Kent marine "purple Tech" to assist with purple coralline and green calcareous micro algae and dropped down to just 5 damsels. So far things are looking good, so how long after I put the powerhead on should I test my water? And can I or should I check it during the time frame (over whatever the period of time for the purple tech to work) I am adding the purple tech?