I'm still pretty much a Newbie but have learned a lot and would like to share some insight.
There are ONLY a handful of things you need to control to have a successful grow. If you keep these within the ranges specified below everything will fall in to place. You won't have issues with bud rot, mold or pests.
Light - the more the better! MAX out your light/lumens. This is easily accomplished with a 1000W hood/ballast. CFL's are good but will NOT produce the type of harvest you are expecting! Get a hood that is air-cooled this will help a lot with controlling temperature. Digital ballasts are easier on the bulbs during startup, make virtually zero noise and emit very little heat. It has been my experience that digital ballasts are more reliable and last longer. They are also more expensive, but you get what you pay for.
Air temperature - no higher than 85 degrees daytime and no less than 70 degrees during the dark cycle. Do whatever it takes to maintain the temp within this range. With CO2 you can run a few degrees warmer during the light cycle, not to exceed 90 degrees
Humidity - 40% - 55%. A higher RH during Veg of 55% is ok, you MUST lower your RH during Flowering to 40%. I have even seen some Flower at 35% RH. This helps to prevent mold/bud rot.
Water Temp - 65-70 degrees. For ANY Hydro setup a water chiller is a MUST. Especially under 1000W lighting in a room at 85 degrees. Your water temps will easily exceed 80 degrees and needs to be chilled. The higher the ambient room temperature the lower the water temp needs to be. Not to drop below 60 degrees.
Air Quality - I use 3 small fans in my grow room. I also use CO2 with a PPM meter set to keep the room at 1500PPM. This works great and my PPM ranges from 1350-1500 ALL THE TIME!!! The fans circulate fresh air as well as the CO2. It also helps to prevent mold/bud rot and reduces the temperature around the plant canopy.
PH - Buy a QUALITY PH meter and keep your PH between 5.8 - 6.3. A little PH swing is ok and I think actually helps strengthen their resistance to PH changes. Always make MILD adjustments to PH levels.
LST - low stress train your plants!
Nutrients - Almost ANY nutrient solution will do. Spending more $$ rarely equals more/bigger buds. Start with something inexpensive and work your way up. MORE IS NOT BETTER!!! You WILL burn your plants. I always start out at 75% dose and QUICKLY work my way to 100%. I know many people who start their grow at 25% and run it like that for a few weeks and then jump to 100% and don't understand why their plants look like a sun dried tomato. I believe that running less than 50% for too long has a negative effect and you will have a very hard time increasing it to 100%. Start out at 50-75% and immediately work your way to 100% within the first week - 10 days. Also purchase a QUALITY TDS/PPM meter to measure the total disolved solids in the reservoir.
Seeds - crappy seeds = crappy buds. The only thing bag seeds are good for are PRACTICE. Collect bag seeds and use them to practice germinating. Once you have them germinated grow them for a couple weeks. You will get to see how the environment is impacting them, how your nutes are affecting them etc.... Then after a couple of weeks you can pull them up and germinate the expensive seeds. QUALITY seeds with known good GENETICS are worth the $$. BUY THEM!!! You won't be disappointed. Personally, I use Attitude for my seed orders.
Read ANY posting by
Professor Marijuana - this guy is an Encyclopedia of Cannabis. I read, read, read his postings and can directly attribute my success to the information he shared on these forums!!!
OBVIOUSLY the 'tips' I have listed are NOT the ONLY things necessary for a successful grow but if you have these nailed, you will be prepared to address anything else that comes up.
Also, pickup/download a copy of Ed Rosenthal's Marijuana Grower's Handbook. EVER THING I typed above is in that book. Read the damn thing!!! I did and look at what I've done. For a 1st time hydro grower I'm doing VERY well.