Experience with Sunshine #4?

I am growing in SunShine#4 as advised by a friend of mine. My plants about in between 7.5 to 9.5 inches, in small starter pots. I am giving them a half a cup of water every 36 hours, and they *still* seem to be drying out real quickly. I must be losing loads of water through the leaves, because the soil-less mix is still moist when they start to dry out. Anyone had this problem? What should I do... give 'em more than the 1/2 a cup? I would prefer not need to water them every 36 hours. Right now I only have four clones, but getting another thirty five tonight. The four clones that I do already have, the rock wool is a tad closer to the surface of the pot than I would like. I am supposed to bury that puppy in there as far as I can right? So the plant comes out of the SunShine a little bit below where the first leaves were starting to form? Thanks in advice guys.