I have two Mars Hydro 720 reflectors. Currently just running one of them.
Yes and no to the air intake. I haven't had a chance to install the intake vent because I'm waiting on a filter for it. But my drain table 3/4" run off pipe runs out of the room and allows some fresh air and I'm in and out often.
Temps have been between 65* to 80* I'd like to keep them more consistent but still trying to dail that in. Humidity has stayed between 50%-75% but usually right around 50%. I'm going to be picking up a dehumidifier soon because I expect my RH to rise as the plants get bigger.
Your making a few mistakes here brother..
IMO WHICH MEANS IN MY OPINION...
you need to back them lights off to 3 foot above the plant top canopy.
Im concerned that you are not getting enough c02 in there.
The plants are suffering from what is called miniaturization.
Which is usually caused by the light being too intense..
Im sure you know that
mars hydro light are lower quality,
because of that ive noticed a few mars owners saying they had to back the light off the plant during veg, esp early veg...
Also I WOULD NOT top them plants as you need to get them healthy.
As for your space, your groom.
I like it and it will be excellent moving forward.
If i was you I would work towards getting a c02 valve $50
and a co2 controller $ 300
and completely sealing that room up.
That Ac will cool them lights and that room easy!
Also try not to let your temps drop under 70
the higher temps in veg (low 80's) is fine.
After week 3 of flower is when you want to drop them to 75 to 77
rh in veg is fine 50 to 75% I run 65 to 70% rh in veg and 60% thru flower till week 7 then i drop rh to 55 week 8, and 50 week 9.
I would also toss the soil and go either coco, or rdwc...
I think these plants are so stunted,
that i would start some news ones in something other than super soil...
JUST MY OPINION HOMIE...
Welcome to the farm!