What's your recommendation for going sterile? I have read H2O2, bleach, zone, chlorine, chloramine, physan 20, naccosan, UV, RO, UC roots, root guard, ect ect.
I think a lot of people assume problems are coming from within their systems, light leaks, etc., when really it is the water itself..
just my experience & opinion:
H2o2 downsides are costs, half-life, & fine line between effectiveness & toxicity
bleach @ low dosages can be cheap and effective, though also has potential to be harmful. effective at fairly miniscule doses in most cases.
zone is useful against some things but IME won't combat 'bad water' scenarios like ozone/bleach/etc will. more of a bandaid for light leak algae or other minor stuff. it's chloramine, which has a good half-life, and copper sulfate i believe.
physan 20 is a bit different. everything-cide that can be useful, but doesn't provide the liquid elbow grease factor (oxidation of buildup) that strong bleach does. be careful with this stuff, it doesnt take a lot of leftover residue to ruin/kill your plants.
UV can be effective but where you will run into problems is in the root mass itself, and it won't do anything for stuff that doesn't pass thru it.
RO doesn't really kill anything in your water, but in my experience it alone can reduce the amount of iron bacteria after it goes through it. if your iron is real bad, you'll need a greensand filter or try something other than water culture.
UC roots...i'd never tried or heard of until I got back into reading forums. No CC stuff at any of my local shops. Was running regular ol germicidal bleach for over a year but have found 24 grams pool shock per gallon of RO, used 1-3ml/gal, to work awesome. Using between 2.5-3ml/gal at changeouts and roughly adding that amount back to match every top-off. ymmv
and last but not least, ozone... Going to RO & treating my holding tanks with ozone ended up being a major breakthrough for my UC'ing. I know of 3 people with old 8 gallon systems for sale; although I didn't firsthand witness their troubles, water quality was definitely a factor. Kendog's setup intrigues me greatly and am very interested in seeing the results.
if you have bad water that doesn't really wreck an RO, an easy but manual way is to get 55 gal drums, 275s, whatever, as holding tanks. Bleach them fairly heavily on a cycle where you give them about a week to bubble off (with air stones). Once it passes the nose test it's good to go. You can also cheaply and effectively deploy ozone w/ holding tanks, but not within a living area, as ken's troubles with off-gassing have illustrated.