For you Physan users
 

Is physan 20 something that can be mixed in the water for general watering purposes or will it interfere with the proper growth of the plant? I am thinking about using it in a reservoir for a misting system, where some of the mist might hit a plant and return to the reservoir.

Good question, I'm wondering the same thing in regards to just regular watering of the soil in potted containers.

I know that there's a thread somewhere on the OB that answers this question. I think the answer was, while there are always side effects to chemical use, people do use small amounts of physan to treat the water supplies that they use on their orchids.

There is a much better, fuller discussion of this somewhere on OB if you do a search.

-J

Briefly, Physan 20 is relatively harmless if used according to the directions on the label. As a matter of fact, chances are if you swim in a properly treated swimming pool, Physan 20 is present.

I have had too many disasters using physan on my plants,I only use it for sterilizing pots and stakes.
I use H2o2 30% 20 mils to 200 liters water to clear the feed water of any nasties I let this circulate overnight

The label recommends as much as a tablespoon per gallon for most treatments of infected plants. That's roughly a 0.4% solution. I try to avoid using more than a teaspoon per gallon, one-third of that concentration.

However, over the last 6 months or so, I have been experimenting by adding about a cup per 5 gallons of fertilizer concentrate, which - when fed through my metering pump - comes out to be a final concentration of about 0.01%. I have not seen any infections in the plants, algae growth does seem less, and I have seen no issues with the plants.

I've never heard of any 'disasters' using this product, when used according to directions. I'm curious to know what exactly what happened?

Love, love Physan20
 

I always wonder why people don’t just contact the manufacturer, or at least read their website. Their phone number is right there for folks to call from someone like Physan20 all the way to the largest chemical manufacturers — they all have customer service departments. I use them a lot and for the vast majority, are very friendly and helpful. If they don’t have the answer because it’s an unusual one, I send an email and ask if it can be passed to quality control, to the engineers, or anyone who might have access to more detailed information than customer service.

But the answer for reservoir use is as follows, the first is found under Reservoirs under the Applications tab. The second is found under the Orchids tab.

“Physan 20 can be added to the hydroponic reservoir to prevent pathogen growth in the reservoir. We recommend starting with a rate of 1 teaspoon per 50 gallons of water. Normally this will be sufficient; however, this can be increased up to 3 teaspoons if needed. This maintenance program should be employed every 7-10 days”


“RECIRCULATING OVERHEAD WATERING SYSTEMS
During the last 2-3 minutes of watering, use PHYSAN 20 solution as a preventative program. Due to variations in growing conditions, use PHYSAN 20 every second to fourth watering. Will control algae in nozzles.
USE: 1 ounce PHYSAN to 20 gallons of water.”

While I don’t use Physan20 in either of the two exact same situations above, I do put it in my rainwater or RO collection barrels especially July and August when it’s super hot that I get concerned about algae, or the water molds (Phytophthora and Phythium) which are two nasty issues in potted plants and are responsible from everything like the Irish potato blight,to the dying of oak trees and kill millions of dollars of plants in greenhouses every year very quickly clearing out entire crops. Physan 20 is used by many non-organic hydroponic folks use all the time. I use it anytime there is lot of rain called for - prior if possible and certainly afterwards. When I see even a bare notion of crown rot and for lots of other uses as noted under the Orchids tab.

And the active ingredient (ALKYL DIMETHYL BENZYL
AMMONIUM CHLORIDES C12-C18 and ALKYL DIMETHYL ETHYL BENZYL AMMONIUM CHLORIDES C12-C14) in Physan 20 is the exact thing used to disinfect your hospitals, nursing home, restaurants, food processing plants, and anywhere a safe disinfectant is needed that does the job but won’t hurt people, animals, or plants. It’s what’s in many hand cleaner, dish soaps, and wound care products that states it’s antibacterial. The list and application is tremendously long.

The website, under Applications tab, look under Orchids and it tells you how to use for and at what dose for each purpose whether using for pots, or seedlings out of the flask,repotting, or bad case of crown rot, etc. if you then go read under the other tabs, including Greenhouses you will learn alot on using it.

Like Madphrag, I’d like to also know the circumstances where someone has had “disasters” when it was used as directed. Hopefully they were using Physan 20 and not Phyton 35 etc. They are not the same product — not even close. Though both have their purpose not for use in all the same ways. And

Many people I find try to use a product the way they used a similar one and that’s wrong. Always read the label even if it’s the same active ingredient and especially if someone tells you, oh it’s the same as such and such brand and it’s cheaper. Well it’s cheaper for a reason. Sometimes it can be just advertising but you need to determine that for sure. Is it really the same, and can you tell for sure that’s why. It can be slightly formulated differently, it may be because it’s got proprietary ingredients they don’t have to tell you about, it can have another ingredient added in, and here is what gets most people — it’s at a stronger or weaker strength. Meaning it’s needs more or less water mixed in. This I have seen cause many “know it alls” a lot of trouble. You know the ones who refuse to listen to you,refuse to read the label, refuse to ask for help. Or they just flat believe,if a little is good, then an extra teaspoon is better, or worse they don’t measure at all — just pour out “what they think is a teaspoon or 1/4 teaspoon, etc.”. Don’t mind me but these are the people who really make me mad because they are killing beneficial insects, birds, etc and are needlessly contaminating the ground, and the water table which affects someone’s wells. And it will seep down to affect creeks, streams, rivers etc when everyone does it. Sorry I will get off my box.

Rosebud... Thanks for pointing out that the manufacturer's site has lots of good information. One can stay out of a lot of trouble by just reading the instructions!! Then if you need to do something different, know WHY you're doing what you are doing and the possible negative effects. Good advice for lots of things, not just treatments for orchids. (In the world of IT of tech support, a favorite acronym is RTFM - Read The **** Manual)

As far as experiences indicated in prior posts... note that this is a REALLY old thread - the last post prior to yours was in March, 2011.