You might get some, clouds, usually that is when the tank is cycling, the nitrifing bacteria over produce and what you see is the extra nitrosomas that are not needed to do the job of the cycle, as they die, not to be concerned with, what you need in the tank for the amount of waste you have stay alive, the tank will clear. As far as the diatom algea, It should be gone in about 2 to 3 weeks, but in about a week you will notice it going away. Also, there is a burn in time on your bulbs where they burn funky color, usually a color that promotes algea growth. On my old tank I had 2 250 20k mh, and my tank was perfect, until I started getting little algea, then more, then hair algea. I put in new bulbs, and bam, back to norm. The burn in is usually 100 or so hours. I have 2 65 watt actinic power compacts that TOTALLY changed I mean visually to the eye, color after about 2 weeks and the diatom went away. Oh yeah I forgort to tell you, started with 2 55 one white, one actinic on reef. Added 10k 250 mh pendent in canopy, with NO actinics to go with it, got brown diatom. About 2 weeks later when my 65 actinics came in I got the diatom again, until they changed color. Funny get algea at the begining of a bulb and you will get it at the end if you run them too long... Good Luck