Glether's Easy NFT (Nutrient Film Technique) is easy to construct with materials available at home improvement stores. The system uses 4 vinyl gutters run parrallel. 4 drip lines feed the 4 gutters and up to 60 plants.
The gutters are run in 10 foot legnths, with 2 inches of drop over that length. The gutters drain into a 25 gallon res. Overgrow recommends the use of light proof covered gutters and reservoirs to avoid algae issues.
The system uses 3" rockwool cubes set directly into the gutters. Covered gutters are recommend (gutter covers are available at most home improvement stores) to avoid algae problems and root illumination issues. The drip lines feed at the top of the gutters and drain back through to the reservoir. The system employs a Little Giant NK1 210gph water pump. The two center gutters drain straight to the reservoir. The two gutters on the outside have 90 degree elbows, as shown in the image below. The reservoir is aerated by a whisper 400 air pump and air stone.
Glether uses multiple 430 watt Diamond lights and claims to harvest on average 14 to 16 ounces per light! One additional tip, he notes that clogged drip lines are easily cleared using compressed air.