Yes, you would have to leave an opening of 2 or more square inches to allow enough air to replace the air removed. If you tape the flap open you should be ok.
The air that you will be removing from the tent using your fan has to be replaced with fresh air. The only way to do this is to have a open hole, preferably as low to the ground as possible for cooler air. Air removed always requires makeup air.
I asked this exact question of Fatman and correct me if I'm wrong Fatman, the response was that the additional amount of ammonium nitrate was negligable compared to the overall concentration of the mixture. Basically, it contains 15.5% ammonium nitrate in the calcium concentrate. The small...
Fatman,
I checked out your formula thread and noticed that the waste to drain Veg formula was missing. I scanned this thread and failed to locate it as well. Did I miss it? If so can you point me in the right direction or list it in your formula thread. Very much appreciated.
They ask you to specify plant type...should you include type of strain? LOL. Just kidding, I guess all they need is the formula and a simple tomato plant would suffice.
Fatman uses "waste to drain" method. That's what post #62 formula is for...the formula you are comparing to is for recirculation systems.
My appologies fatman I didn't notice you were online.
Fatman,
Would you be able to get taller plants with the same node spacing if you were to distance the light a little further from the plants (essentially stretching the plant). I know that you keep your lights 2 to 3 inches from the canopy top and was wondering if the close node spacing was...
Fatman,
It would definitely be a great way to control the nutrient feed in the root chamber assuming the drop size is within the acceptable range. I would test the system in an empty chamber before attempting a grow with it. It's been a long time since my thermal dynamic classes but something...
I thought as you at first....that this would be a good idea and thats why I looked into it a little further. I've been using the logic and calculator supplied buy a nozzle manufacturing company location in the U.S. I attached the link below...
http://www.ispray.com/application-humidification...
Fatman,
 
I revised the numbers to better reflect your conditions. I don't no your chamber size so I used 4' L x 4' W x 2' H for 32 cu.ft to be humidified ft/hr at 100% RH. The room temp at 95°F and chamber temp to be 95°F. With the system on time at 100% you would require a flow of...
I've done a little reseach and found to maintain a chamber at 68 deg. F at 100% humidity you would have to constantly supply 105 deg. F nutrient temp. As soon as you go below 105 deg. F dew(rain) would result then you would be in the 21 micron and above range.