There is about 5" of water beneath the egg crate and all of it is flowing. Water is pumped from the bottom right corner of the tank to the top left corner where it falls over the mesh. The computer fan takes ambient air and blows it through the mesh with water flowing through it and into the tank. When the air flows through the mesh with the falling water it is cooled.
I have two of my neps in there for now and orchids mounted on the back panel egg crate.
Hope this might help some people out and as always, any feedback and tips are welcome.
P.S.I don't have a *working* thermometer and humidity gauge yet, but will update with specs when I get one, but I can feel cool air coming from the exhaust.
40 gallon aquarium tank - bought used on OfferUp, $25 (OfferUp is great for getting cheap tanks)
Tank stand - bought used on OfferUp, $25 Egg crate - Lowe's, $12 PVC piping - Lowe's, $3.21 (for 10ft, I used about 3 ft)
(x2) Excelvan 45W LED lighting panels - ebay, $52 total
140mm high flow computer fan - $7
Fountain pump - Lowe's, $20 3/8" ID Tubing - Lowe's, $7 Plexi glass - Lowe's, $10 Plastic bin - Lowe's, $3
Filter mesh - Pet Supplies Plus, $3 Total: $167.21
The glass is a bit cloudy (one of the bonuses of a pre-owned tank xD). Lights off Inside