Pythium is present in all soils unless recently sterilized, all open bodies of water and most shallow water wells. Their are a few types of Pythium that can be airborne butt these are not strains that typically effect pot growers. If your water came from a treatment plants that use water from open bodies of water such as rivers, reservoirs or lakesn then yes you like have large amounts of Ptyhium in your water. Anyone sayng Pythium will alwys be present likely also does not brush their teeth, take vitamins or practice other common methods of preventative medicine. Chlorine is cost effective, yes, but its reason of use is beacuse it is simple to use, it is economical and most importantly because it works.
The enzymes convert food into a form better utilized by plants, aerobic bacteria (Nitrosomonas) convert ammonia from organic wastes into mitrite then other aerobicbacteria (Nitrobacters) convert the nitrite to nitrate which is the most readily usable nitrogen form for a plants roots to utilize. In and only in a area with a lack of oxygen does anerobic bactteria play any part. Aneraobic bacteria converts nitrates to Nitrogen gas and CO2. In nature this happens in the deep scum layers in the bottom of lakes and in swamps in peat bogs. Septic tanks (key word septic) mainly sre used for the settling of solids but as they are not aerated some denitrfication from anerobic bacteria takes place.with Pythium for food and no more. It requires a mass of organic filth that air can not pass through readily as the aerobic bacteria use up the O2 at the masses surface. The enzymes compete with the Pythiumfor food just as does the aerobic bacteria. The enzymes colonize in the roots so only compete for nitrate and nitrite to any extent. Pythium will only com nsume those nitrogen sources as a last resort rather than starve, there principal source of food is ammonia so they really only compete with aerobic bacteria for ammonia. These bacteria are alos airborne and quickly set up shop in water reservoirs they need not be purchased.
Ptyhium always maintain small populations unless there are large amounts of food. Lessening their food lessens their population but in a system with roots there will always be food for them so they cannot be straved out.
Aqua shield and enzymes - same thing guys just different marketing.
As far as a system becoming to aerobic and controlling Pythium as a result. It will not happen. The amount of DO increasing will not slow Pythium as it is an aerobic organisms that is just tolerant of anerobic conditions. While O2 as a gas can kill pythium it seldon sits out in the open but lives in water or accumalated organic matter or actually colonizes the organic tissues.
Putting it all simply. Good chemically based nutrient growing systems that are well maintained usually only have Pythium populations in low numbers that therefore seldom cause problems. However any system where the roots are dependent upon high DO of ten have regular larhge amounts of root death and those that use use orgainic nutrients have very high levels of raw organic nutrients that support large Pythium popultaions. The oraginic ssytems and DO dependent systems are very much more likely to have root rot pythium events.
While I do not advocate chlorine use with organic nutrients (I do not advocate organic nutrients with hydroponics at all) I do wish it to be known that chlorine can eradicate all Pythium from a system and from water added to a system and that low residual doses ofpyhium can prevent Pythium from resetablishing in a system. It is very doubtful that as the vast majority of commercial green houses use chlorine to kill pythium and then maintain a zero level of pythium in their systems can all be wrong and that those who do not are right.
Like all microbes, nitrifying bacteria are temperature sensitive. Rapid changes in temperature do not produce rapid changes in growth rates. A slow adaptation period, with a lower than expected rate follows such changes. That is scientific fact. At higher temperatures the growth rate does not increase as others would suggest, and by 35° the growth rate begins to rapidly fall off toward zero. I do studies on aerobic and anerobic bacteria for a living folks.
The only thing a rise in temp will do is increase putrefication of organic tissues so as to make ammonia more quickly avialable to the aerobic bacteria and the pythium. However there has to be dead organic matter for that to happen. Good systems do not die back just due to warm resrvoir temsp, Sad DO dependent systems do.
Nitrifying bacteria are especially sensitive to low oxygen concentrations/Nitrifying bacteria and Pyhium are dependent of oxygen for life and for multiplication. Lower the DO and they decline in number, limit the amount of DO and they can not multiply. ie high DO reservoir water is a debit to good aero and hydro systems but a must have for poor DO dependent systems. The reservoir of a good system only needs enough DO to keep the system aerobic. Nitrifying bacteria popultaions and Pythium populations both go through lag pahses in theoir multiplication. Large increases in their populations typically take place over several weeks not days.
Chlorine treatment of water, Regular reservoir changes (every week to 10 days). And for those who like preventative treatment, maintain residual levels of Chlorine. More than anything the best method of avoiding root rot and Pytium problems, quit using deep water NTF, DWC, bubbleponics and small tube or small gutter aero systems where the roots are laying in water in the bottom of the channel or trough.
