How about just buying a cheap one? Here's one:

http://www.bghydro.com/BGH/Itemdesc....HELF04&eq=&Tp=

Can you build one cheaper? Probably. Would it work as well? Maybe. Would it take a lot more work? Definitely.
jamstigator Reviewed by jamstigator on . DIY Carbon Filter ? ? ? help ! ! ! ok i half way done build my grow cab "24" by 24" by 48" i have not put on the top cause i need some thing for order control so does any one know how to build a cheap one????? any plan or pics is great:D :dance: smoke happy:smokin: p.s. never try to build something out of wood if you are high i had to make 2 trips to lowes for wood... i keep cutting the damm wood to short.... oh well live and learn... :stoned: Rating: 5