I have recieved some really coraline encrusted rock that I filled my new tank up with. You can see some of what I believe is white coraline algae in my, "my week old tank" post in the general reef discussions. It was growing fast on a rock that had no coraline algae when I purchased it. Right now I have regular floroucents, one is 24 watt saltwater/freshwater and the other is an eclipse systems lighting that has one white and one blue bulb in it for saltwater. My star pollups don't seem to be all opening up, they have decent flow by them, but my zooanthids seem to be doing well. Anyway I am afraid because I have read things about coraline algae not growing well under MH bulbs. I have recently obtained a 250 watt xm 20K MH bulb and ballast, which I like the blue look better than the 10k bulbs yellowish look. Plus I hear the 20 K dosnt bleach out soft coral as much. Anyway I have these simple test strips and my akalinity seems to be near 300. Don't quote me on that because I am color blind lol. I have no means of testing calcium. I am afraid of my coraline algae dieing off. Should I use the product known as kalkwasser. What levels of calcium do I need and what is a good alkalinity? Thank you very much for your well respected attention and information. Kudos