Eh, for a very small PU operation you can rig up a vinegar + baking soda drip... Check the advanced section looking for CO2 related posts.
I like my tank system but admit that for a space much smaller than my 6x6x6 Borg cube it would be overkill.
stinkyattic Reviewed by stinkyattic on . WTF!!! Hi every one, Dont know whats goin on this time round and its doin my nut in! So here goes........ plants are 3/4 weeks old from clone.Pre ph`d rockwool cubes 600wtt HPS-18/6. NFT,and they`ve been in the system 11 or 12 days. The pump is just a light trickle running only when lights on. Temps are 81 lights on,not too sure lights off temp,but its in family home.... 125mm intake and exhaust rvk`s. On constant.Humidity 40% On the second day of them being in the system I changed the res and Rating: 5