1. Its better to be too cold than to hot - heat is much less expensive than chillers and such. depending on what kind of system you are running temps should be between 62-ish and 68F... thats for DWC - any higher than that and you'll get root rot, which sucks ass. I think other systems may be more flexible, not sure how flexible in terms of too cold though, never ran into that problem myself.

2. You need hyroponic nutrients, and at least a method of checking the ph... the nutes you can kinda guess with, but if you give them too much - you'll never REALLY know unless you have a TDS pen. setting up a successful hydro system cant really be done with things around the house like a soil grow. Some may say you can, but then I'll just put some emphasis on SUCCESSFULL..

3. i dunno if we are supposta give out addys here, cuz I'm kinda new... so fuck it - i'll claim ignorance. discounthydro.com is good - very dependable and discreet. Sometimes people on ebay sell shit for cheaper though... and when in doubt, and on a budget... froogle.com

4. wal-mart sells small thermostatically controlled electric heaters for $20 I have one for my office... they work well. put the ventillation on timers, so there is no fresh cold air coming in during lights off... they dont need it then.

hope that helps! :thumbsup: