I decided to post pics of my grow out tank. Feel free to post suggestions.
85 gallon tank was bought used with melted top rim from a heat lamp falling on it so I removed it. I had two pieces of glass cut for the top and siliconed handles to them. I put a bead of silicone along the top of the tank and let it cure for a few hours before placing the top onto the tank (silicone on top was cured and unsticky but it still squished and created a seal). The side tubes are two 90 degree 3" ABS elbows. I used weldon to glue the fans to the inside of them creating a U. The whole structure was siliconed to the side. False bottom for drainage is just eggcrate with pvc and screen.
The tank maintains about 80-100% humidity and is lighted by a cheap 4 tube t5ho fixture.
The fan blows air one side of the tank with the tube and pulls from the other. It's opposite on the other side so it should keep a steady circular ammount of air flowing. I thought about making a pipe the length of the tank but figured it'd take up too much room using 3 inch fans.
I bought some fairly high cfm fans. They're strong enough for me to consider them possibly too strong. A piece of paper towel taped from the end of the tube to half the length of the tank will stay roughly horizontal with the air flow.
Forgot to ask, does thier placement in the grow tank have anything to do with their eventual placements in a Tank..or is it just to have more plants in the amount of space you have?
Placement within the tank has nothing to do with how they'll be in a viv. They're packed in there atm, though I could put a few more in. They were bought to grow out while I work on my vivs and for possible propagation of a few plants. The tank stays very humid (my room air is very dry). I bought the light specifically for a plant rack but desiced to go with a tank when I found the used one for 55 dollars.
The plants came in looking good but started to get bad due to the humidity (especially the orchids). They're doing fine now.
BTW, I used velcro one-wrap to tie the lamps to the underside of the racks. The stuff is great. Also, the lights were a cheap no-name brand which I've found to have approximately 55-60% efficiency for the 2 lamp setups (up top) and approximately 65% efficiency for the bottom 4 lamp setup (using Kill-A-Watt). This means that 35-45% of the rated watts are not being used (you're not getting charged for them but the lamps aren't using them either so the light isn't as good). A decent ballasted fixture will do much better for light just based on its efficiency.