# Clorox and algae



## abax (May 26, 2013)

I'm having a terrible problem with algae build-up on the concrete floor of
my greenhouse. I've tried Physan with a stiff broom and a wire brush on
very slick spots, but on my knees is not my favorite position. I'm considering using bleach, but I'm worried the fumes from bleach might
be detrimental to my orchids. Any experience...opinions? Good advice
just might save my life. The damn floors are very slippery and I'm an
old person.


----------



## limuhead (May 26, 2013)

I know that Wilbur Chang used to use Clorox as a fungicide on his plants so I don't think it will do any serious damage. Not sure of the dilution rate he used, but he had some of the nicest, cleanest plants I have ever seen...


----------



## gonewild (May 26, 2013)

The fumes won't hurt the plants assuming you use moderate amounts. Spary it on with a sprayer and.... Algae be gone. No scrubbing. I just put a cup or two in a gallon or two of water, it works.


----------



## goldenrose (May 26, 2013)

If in doubt, have you looked into pond products for algae removal?
I'd be gagging on the bleach fumes, thank goodness I don't have an issue in my GH, I started with a couple of anti fatigue mats in the aisle and then Menards had the rubber patio pavers on sale.


----------



## Ruth (May 26, 2013)

My greenhouse is on concrete, and I have the same problem. I have a floor scrubing brush that I attach to a mop handle so I don't have to get on my knees. I use bleach water to scrub the floor. Don't know the how strong. Doesn't seem to take much. It doesn't seem to hurt the orchids. Make sure you open the doors and vents as it smells pretty strong and probably isn't very good for you to breath the fumes.


----------



## cnycharles (May 26, 2013)

making some air movement while using the bleach could help, and before you get to the point of bleaching the floor, you could toss some sand where the algae is so that you can get some traction. roughing up the concrete surface is always a good idea when you are putting it down, also making sure that it's somewhat rounded so that you get drainage instead of puddling/algae. i've seen many people fall where there was a low spot and very smooth concrete, which was as slippery as ice with algae on it. if a low spot is recurring, could use some fine self-leveling cement to fill an area so that it doesn't puddle as much


----------



## abax (May 26, 2013)

Thank you all for the reassurance. Bleach couldn't smell much worse than
Physan. I can turn the exhaust fan on and that will help me. I was just
worried about the orchids.


----------



## Ray (May 27, 2013)

Once you get it removed, you really ought to consider a preventive program.

I used to use bleach as a complete greenhouse dousing (1 oz/gal) - including plants - then later switched to Physan (1 tsp/gal), and now use Zero-Tol RTS. Unlike the other two, it has shown no signs of phytotoxicity in any plants, is excellent at keeping the algae at bay (including in S/H pots), and the mild vinegar odor is of little irritation.


----------



## SlipperFan (May 27, 2013)

I use bleach on the cement tiles in my greenhouse. Doesn't hurt the plants. I even use 1% bleach occasionally when I water to help keep fungus gnats at bay. That doesn't hurt the plants, either.

Zero-Tol RTS is extrememly expensive, and I think it can burn one's skin if you get it on you. I know commercial growers that have used it, but I can't afford to.


----------



## Eric Muehlbauer (May 27, 2013)

Terry Root told me (at the "orchid show" last Feb) that orchids, or at least paphs, are very tolerant of bleach.


----------



## Ray (May 28, 2013)

SlipperFan said:


> Zero-Tol RTS is extrememly expensive, and I think it can burn one's skin if you get it on you. I know commercial growers that have used it, but I can't afford to.



Compared to bleach it's expensive ($23.50 for a quart hose-end sprayer), but not outrageously so. I have a bottle in the greenhouse that I've been using on a periodic basis (~every 6-8 weeks) for close to a year.


----------



## SlipperFan (May 28, 2013)

Ray said:


> Compared to bleach it's expensive ($23.50 for a quart hose-end sprayer), but not outrageously so. I have a bottle in the greenhouse that I've been using on a periodic basis (~every 6-8 weeks) for close to a year.


Interesting, Ray. I've only seen the concentrate that sells, I think, a gallon concentrate. So I just did a google search and found it on Amazon for 29.49. It looks like you have an even less expensive source. 

Do you spray it on your plants?


----------



## cnycharles (May 28, 2013)

you can... i've sprayed straight and diluted hydrogen peroxide on my orchids, and we've used peroxide zerotol on misted cuttings (non-orchids)


----------



## abax (May 29, 2013)

Hmmm...different options, but I'll probably take cheap bleach, turn on all
the fans and run for it.


----------



## cnycharles (May 29, 2013)

one thing that might help deciding for some people is that some sterilants don't disinfect dirty surfaces (that have organic matter on them). bleach does, and peroxide does as well


----------



## Ray (May 29, 2013)

Yes I do, Dot.

The thing about Zero-Tol, or it's pre-mixed version, Oxidate, is that because the peroxide is stabilized, so stays active as long as it is wet, they can get away with a much lower concentration of it while getting better effect.

Dump the 3% stuff from the drugstore on something, and it's effervesced and done in seconds. The peroxide concentration from Zero-Tol and Oxidate is only about 0.1%


----------



## terryros (May 29, 2013)

Get the Zero-Tol concentrate and mix it 10 mL into 500 mL total solution and you have the strength that you need. I use it on each plant each time I water and algae is well controlled. That means I use a lot of the solution and mix up a new 500 mL every other day. I even like the smell (it is weak).


Sent from my iPad using Tapatalk HD


----------

