I tested the runoff: 6.3 going in, 5.2 coming out.

I've never used sunshine #4 substrate, I've always grown hydro w/ rockwool and hydroton. A friend of mine that has used #4 for years told me to treat is as hydro because it is not actually a soil. Does anyone have any experience with this substrate?

Any advice is welcome, thanks!
skitze Reviewed by skitze on . leaves curling down - please help!! Your Equipment: .1) Type and wattage of lights. (MH, HPS, CFL's, tube fluorescents, LED's) - 1,000 watt HPS .2) Distance from tops? - 3 feet .3) Reflector type? (cool tube set-up, bat wing, enclosed reflector, bare bulb...) - radiant hood (open) .4) Is there a consistent fresh air supply? - intake is hooked up to controller, holding temp at 75 F. clicks on every 10 min for at least 10 min. .5) Do you have an exhaust fan and a circulation fan? no exhaust fan, yes circulation fan Rating: 5