Help me decide on replacement bulbs for my Giesemann Infiniti 4ft fixture, it is on a 120 tank. Currently has all Giesemann bulbs, they are 2 250 DE 20k (22k) and 4 T5's that are their Pure Actinic. I need to replace all, they will be 12 months old in a couple of weeks, trying to stay a little blue but looking for best growth with SPS as tank is 95% SPS. I would like to stay with pure actinic style of bulbs for the T5's, but thinking I should go to 10 or 15k instead of 20k for the DE 250's. Not too worried about price.