I recently just switched to hydro, using flood and drain bucket system (12 4 gal buckets per 55 gal res, flo n gro). I am using house and gardens nutes, a, b, root exel, algen extract, multi zen, drip clean, bloombastic, nitro boost, superthrive, cal mag and have bud candy as well for use in flowering. I have been debating using something like h2o2 as a preventative to baddies forming in my systems. As of now I am just using ro water and nutes. I use 6" grodans and large perlite as medium. I noticed some of the roots look stained brown.. smelled fine (well smelled earthy like). If I wipe my finger over the roots hanging down whatever was making it brown (maybe nutes?) it would wipe off and they would be white. Do not feel slimey at all. *** I went and bought some h2o2, 29 percent at the grow store. I am using that now in the res's. Another big concern for me is how often to flood. its a ebb n flo system (gro n flo). Has a 55 gal res, 12 4 gal buckets/net pots. I am using 6" grodans and large chunk perlite as medium. I know the grodans will hold quite a bit of water and not sure how often I should be flooding.. I have been flooding 3 times a day in veg but seems it may be to much.. plants look ok. but not as good as they should/could be. I have lowered it to once a day now and will see how that goes. I veg for 3 weeks (get plants to about 20-24") before going into flower room, 19/5 light schedule. I veg under 3 600 watt mh's and flower under 6 1k's hps in raptor hoods (vented hoods in veg as well). Flower room has 3 flo n gro setups, doing 3 runs of 12 for a total of 36 plants, cut down every 3 weeks this way. I have been doing this in soil for the past year and just switched to hydro. temps in flower room are 75 with lights on, 68-70 lights off, temps in veg room are 77-79 lights on and 70ish lights off. How often should I be flooding overall do you feel? ** Just finished reading almost all of al b.'s posts in this thread and noticed you are now using sure to grow medium. I am going to try to get a hold of the 6" blocks they sell and use those for now on.. seems like a better alternative to the grodans.. how often would you flood using the sure to grow blocks in perlite? Another thing.. all the nutes/additives I have.. I see you mainly just use base nutes, A and B.. I was probably ill advised by friends and grow stores and online and paid a TON of money for stuff like root exec, algen extract, bloombastic, nitro boost, AN's bud candy and so on.. Should I just ditch all this stuff and just run A and B through veg and flower? Which house and gardens nute would you run during flower on top of A and B? I see you run something special for week 5 on your grows. I was told and have read bloombastic is good for this time in flower, I'm not there yet so have not tried it.. but at 200 a liter its pricey. In soil I vegged to 24".. plants end up around 5' in flower but I yield about 4 ozs a plant of nice dense crystally bud and plan to continue growing to these sizes now that I am in hydro. I have started lollipopping now as well, only did a little bit of this previously. As I said I have been using ro water all along.. which again is probably not needed from what I have read in this thread and may switch to just using tap.. water here is roughly 170ppm (have to verify that again, been awhile since I checked last). Having 4 55 gal hydro res's and 3 45 gal just ro water res's for water changes etc is kinda annoying, would be nice to ditch those 3 extra containers and just use tap for everything.. plus won't need to be buying cal mag anymore. All your info has been great btw, thank you! Really helped a ton.. and made me realize just how much fuckin money I have wasted it appears lol. thanks!