dude... dont ever use that physan 20.... dont get me wrong, i always have a bottle....but what i meant by dont use...is.... that is the last option aka the nuke !!!!!!!!!!!!!!!!!!!!
i would only use it for extreme pathogen and pythium cases. that shit is a serious 'cide. algacide, bactercide, vircide aka ALL the 'cides LMAO!!!
its a nice weapon in the garden, but pick your battles. and know what you are using as thas the end all type of deal.
if you are looking for a rooting stimulant i would go either with H&G Roots excellurator or canna's rhizotonic. Either or works... combining both, imho would only be a waste of money. If you had to pick one, i would go with the Roots Excellurator over the Rhizotonic for the simple fact of RE has the ability to rid root rot.
SM90 is a root maintenance nutrient supplement as well and it also handles small bugs something like a light fungus gnat infection...
however i would stir clear from the sm90. most of these products are just bandaids and snake oil. A bandaid will just hold the problem and not fix it.
You have a 1/2 hp chiller bro. Use that bad boy. Those are the only strong points for those type of nutrients, with the exception of H&G RE and/or Canna's Rhizotonic. There is nothing i love more than a rooting stimulant.
If you are worried about pathogens, and your chiller is still keeping your water chilled...then it is more often than not light leaks somewhere and it will be algae blooms or something algae-ish instead of pythium perse. Pythium isnt as strong in 65F water however, it can still grow in those temps.
furthermore, you have one of the best, natural ways to give roots all they need. you have a 1/2 hp chiller and you have a massive air pump. D.O. (dissolved oxygen) is relative to the temperature of your water. No matter how much air you pump into your reservoir it wont matter unless the temperature of your water allows you to dissolve the gas (oxygen)
hope that helps :D
