I have set up a room for my very first grow. I chose to roll with a drip system for many reasons, mostly due to convenience. Below is a link to another post I made in the growroom/design board, I asked the same questions in this post and there are pictures so shoot on over to it if you'd like. http://forum.grasscity.com/grow-room-design-setup/265587-wondering-how-much-your-growroom-will-cost-might-help.html Here are some questions I have. 1. I am planning to have my drip pump run 15 minutes on for every hour it is off. The timer I am using is conveniently set up for 15 minute on/off cycles. Is this a good drip schedule? 2. Is it okay to have my intake coming in from another room in the building, as long as the air is 'fresh'? I really don't have the option of intaking air from outside. 3. My ventilation fan is rated for a 5 minute cycle time in a room bigger than mine, so the fan is more than good enough. My question is, should I keep it on 24/7? What's a good schedule for the vent fan? Should I have it on more during light-on? 4. How do you know when it's time to change water? Will the ppm or ph go crazy? Will I know by smell? Should I just be safe and change it every week, or two weeks, no matter what? 5. Is there any way to chill my water without the use of ice or a water-cooler? Is there anything I can do to the tub, installation, aluminum tape, anything to drop the water a degree or two more? The water is at about 77F with the light on for 18 hours. Is 77F too warm? 6. Is putting the little rockwool pieces in the big rockwool pieces REALLY needed? After the plant is starting to root out of the rockwool is it okay to just let it set in and root out into the clay pebbles or should I put it in the bigger pieces of rockwool, then put those in the clay pebbels? (effectivly having to remove a lot of clay pebbles. I only have 5.5 inch baskets so I think its kind of wierd having the giant pieces of rockwool in them cause then there will barley be any clay. Again there are pictures in my other post I linked to up above.