Thanks for the reply. My ph is 6.2 I think... I'll double check when I get home. I was looking at a chart of nutrient availibilities in relation to Ph and noticed that calcium is only available for 5.0-5.8 for hydroponics. I've lifted the inner buckets to check for roots coming out of the small holes and haven't seen any yet. I'm thinking I should lower my ph to 5.6ish and not add any calcium yet to see if that helps? The room is 73 at night, 78 during day..the rez is outside of boxed off room and is a bit cooler like 73 probably. I actually have a digital tds pen tool. Maybe I'll try to check out my roots a bit more. Anything certain I should look for? Browning or burnt tips or what? Thanks dude.