How to cool a makeshift orchidarium

[RandiRae]

I am currently growing phals, a dendrobium, and random catt/laelio youngings in a covered 75 gallon tank nder lights. I have several issues...answers to any of them would be appreciated!

1. Due to living in an apartment, the temperature is fairly constant. The tank sits around 78 degrees during the day and 74 at night. I don't know how to cool the tank at night. I've tried inserting a computer fan, although it moves the air, the temp doesn't decrease much.

2. I have fluorescent plants lights (the kind purchased at Lowes)..the older ones (t8's?). The lights are about 12-15 ïnches from the phals and about 5-10 inches from the others (some are mounted, others on pots to raise them higher).

3. I've read that the watering should be decreased in the winter...but due to the warmth of my tank, the orchids appear dry. The humidity registers between 45-55 %. Should I mist or water? The bottom of the tank has rocks. I add water but the humidity rarely goes above 60%.

Thanks for reading. I've been attempting to grow orchids for years...never have I had a plant bloom! Many of the phals appear to be healthy (the rest are touch and go). I just feel humiliated for not being about to get a phal to bloom - they're supposed to be the easiest orchids to grow!