Ok so I'm a first time (well bought all the stuff 8 years ago and got paranoid, sold everything) grower and I have been reading/watching many uni/college lectures on plants in general and growing indoors in general, here are some of the questions I need answered, because everyone's answer varies so much I can't seem to get a straight one. 1. I've heard the air in the room should be taken out every 1 minute, another source said every 5 minutes, many people say at night they don't keep the fans on, so.... what is it? I know plants need circulation, so should i just turn them down to low when the lights aren't on or is it actually safe to have NO circulation (interior/exterior) (other than oscillating fans in the room) for 6 or 12 hours? 2. I've heard chlorine is bad also clorimite? but I read (I forget where) chlorine is actually a micro nutrient (or something that helps the plant) for the plant. I am using soil and I have the "General Organics GO BOX" and on the box it says keep water UNDER 75 Fahrenheit (according to a review cold water keeps the oxygen in better) also it says no PH adjusting required, if I just use those products the Ph should be 6-6.5 according to a youtube is this true? 3. Filtered water VS. RO Water: I heard Brita Fileters and verified "Ion Exchange" takes out calcium and magnesium and turns it into something else (for drinking water) so..... which is better RO or Filtered? I have CalMag I'm sure filtered (Brita) should work fine but does anyone know more about this? 4. I'm trying best to make it an "air tight" space with the white/black 5.5mm plastic taping it together for each sides of the wall with gorilla tape, mainly because I heard it's favourable to have a NEGATIVE AIR PRESSURE to prevent fungus or mold? (specifically a 4:1 negative air pres ratio) 5. I'm growing in a basement so its cold but I've managed to hook up the exterior air to the old chimney, its a 400 CFM fan, there shouldn't be a problem pushing that much air (with a carbon filter on it and 2x 90 degree turns) out correct? Or are chimney's not a good exterior vent source because of the space or something? 6. By looking at these questions am I taking everything to literal, that everything HAS to be done right to get a good yield. BTW I'm using a 1200w Mars II Pro LED, and in the other space (connected to this space but separated by the plastic sheeting) 2x 50w T5 "Sun Blaster" veg lights. I have a total height of 67" did I just fk myself over by buying a 1200w LED or will it work at that height fine and not burn (or harm) my plants? Any tips for the MARS II PRO or LEDs in general I'm growing Feminized White Widow (not autoflower) or any tips for the strain? Thanks, much appreciated.