Help!!Waterfarm Continuous Drip System tips

i have a store bought waterfarm ring drip system with reservoir and the grow chamber filled with hydroton. I just picked a clone up in a 1 inch rockwool cube. I am going to transplant it into the hydroton. How often do i water i have read and heard so many things. i have been running another clone in the same setup with the drips running 24/7 and some of the leafs are curling but not all. I am wondering if it is the splash, i recently buried the drip ring to prevent that. I have already killed 2 clones in the system, i checked the PH and the PPM and everything is good. The first one died overnight and the second one survived overnight and next morning but was totally dead by the evening. aslo because this clone wasn't very tall and sat low to the hydroton i think it could have possibly the splash killing these clones. also is it ok to leave just the very top of the rockwool exposed so its level with the hydroton, i have heard that helps with the rockwool getting to soggy. any input would be greatly appreciated