I'm really not trying to figure things down to the gnats hair but I did do the math before starting.

I'm using a 35 gal tank and wanted a 3% mix. I put 28 gallons of water and 2 1/2 gallons of 12.5% SH. I then added 4 cups of Green Wash.

My mix ran down the roof and didn't really "stick" and it didn't clean the roof. The stains were moderate to heavy and the areas where I walked I did leave shoe prints. I rinsed (no gutters) up about 6 feet after about 35 minutes but the roof still looked almost as bad as when I started.

I assumed my mix wasn't strong enough but the math works out for me....any thoughts?

My Figures were:
8 Gals. of 12.5% into a 100 Gal. tank would = a 1% mix (So 24 gallons of 12.5% = 3%)
So for every 10 gallons of water I need .80 gallons of SH to make my 1%
.80 x 3(%) = 2.4 gallons into a 30 gallon tank

Green Wash is 128 ounces into the 100 Gal. tank or 12.8 ounces per 10 gallons.
12.8 x 3 = 38.4 ounces

1 ounce is 0.125 cups so 38.4 x 0.125 = 4.8 cups (so I was .8 short in my mix)

Doug,

In a 35 gallon tank each 3.5 gallons of 12% bleach will account for ROUGHLY 1% of mix. So to make a 3% mix in a 35 gallon tank you would need about 10.5 gallons of 12% bleach and the rest water with about 35 ounces of Green Wash.

You need a 3% mix to clean a shingle roof.

http://www.softwashsystems.com/page_mixology.htm

AC

So......what you're really saying is I failed my math test.

I got it now.....thanks.

This is how I would do it. If I'm out of order, let me know, please. Some may think I'm too simple...

It may say 12.5%, but it is easier to do in your head if you just call it 10%.

3% is about 30 gallons of bleach for every 100 gallons of water.

35 gallons is roughly 1/3 of 100 gallons.

1/3 times 30 gallons = 10 gallons of bleach

1/3 times 70 gallons of water is roughly 23 gallons of water

1/3 times 64 oz of GreenWash = 21 oz.

When you add it all up there is just short of a full 35 gallon tank. If you really want to top it off, go with a 2:1 ratio, or just add another 1 gallon of water and .5 gallon of bleach. Tweek it from there.

One thing I do find aggravating is it seems like in some places it says to use 64 oz of GreenWash and other places it says to use 128 oz. of GreenWash per 100 gallons. Which is it????

I'm betting my whole pile of chips that it is 64 oz per 100 gallon. Anyone want to raise? LOL

64 is what I have always understood to be correct vic. But it also depends on the severity of the cleaning.

Mike Wedge wrote:

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64 is what I have always understood to be correct vic. But it also depends on the severity of the cleaning.

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Thank you, Mike! That's a keeper.

My goodness, 128 oz is actually a whole gallon! 

That's all I have right now, and I want to make more than one tank with it...

Vic,

it is 64 oz per 100 gallons like Mike said. You will see that sometimes you will want to add more. Especially for higher pitched roofs, white three tab shingles, and the most important in your area....a lot of moss.

Kristofer Wegner wrote:

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The easiest way i remember the mixology is:

1 gal of SH for every 10 gal of mix is 1%
2 gal of SH for every 10 gal of mix is 2%
3 gal of SH for every 10 gal of mix is 3%
4 gal of SH for every 10 gal of mix is 4%
your greenwash is always 6.4oz per 10 gal of mix unless you want a little extra cling
hope this helps

Kristofer

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Well said, Kristofer. I submit us Powder Puffs can go by:

10 oz. of CH powder for every 10 gal of mix = 1%

20 oz. of CH powder for every 10 gal of mix = 2%

30 oz. of CH powder for every 10 gal of mix = 3%

40 oz. of CH powder for every 10 gal of mix = 4%

Also, I believe that for a 100 gallon tank, that translates into: 1% = 100 oz. of CH, 2% = 200 oz, of CH, etc., etc. and so forth...

John Aloisio wrote:

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Vic,

it is 64 oz per 100 gallons like Mike said. You will see that sometimes you will want to add more. Especially for higher pitched roofs, white three tab shingles, and the most important in your area....a lot of moss.

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Thanks, again, John!

My goodness. I was trying to shut up and learn in here, but I've been talking/typing more and more.

But I'm getting some great answers, and really appreciate you guys! So I keep rambling ;)

I understand how higher pitch can cause quicker runoff, but not sure what white 3 tab shingles do.

Are they slicker than regular black asphalt shingles?

We have some moss here, but I'm more in a desert/farmland area. The Western side of WA and OR is more cool and wet.

No problem Vic. That is why we are all here. 

The white three tabs typically take a little more effort to clean, just due to the light color of the shingles.they tend to look the worst when infested and the best when cleaned up.

Vic,

Here are pics of one we just did last week. 

John Aloisio wrote:

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Vic,

Here are pics of one we just did last week. 

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Wow, hard to believe it is the same house, LOL!

Good job. That was an awfully dark roof, and very steep.

Did you "pole it" from a ladder?

I wonder, John, does the extra GreenWash give you more traction when walking a roof?

It was cold last week. How cold can you do this cleaning? I'm a snowbird. Gimme FL, baby!

Thank you for all your sharing. Big help to us newbies ;)

We walked the front center roofs, they were an 8:12 so that's not too bad. The rest of the roof was shot from a ladder, mostly a 10' step ladder. Sometimes the GW does help with traction. If it is an older shingle you need to worry about loose granules that will cause you to slip more. We try to shoot everything from a ladder when possible these days. We had a break in the weather here last week and got a 46 degree day, so we worked. We have cleaned down to 35-40 degrees, with a sunny day and pixie dust. It's just not much fun when working with water on those days! When cold you have a longer dwell time and might use more chems. 

I add up to 1.5 gallons of Green Wash per 100 gallons of roof mix with the heavy moss up here.

must be nice in your part of Jersey I still have a foot of SNOW on the ground and roofs 

BTW there are cheat sheets on the side of a jug of GREEN WASH just keep in mind its based on a 100 gallon tank.

We always use a little extra GW in the mix since the good stuff is in the surfactant ie: algaecide, biocide etc.. GREEN WASH alone will KILL algae and spores it just takes time!

check out the roofs in my area 

Matt Lancaster wrote:

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must be nice in your part of Jersey I still have a foot of SNOW on the ground and roofs 

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And even more up here.

Hank

MATT, you might be a little heavy with the CH on that roof...lol

THATS FUNNY!

Thats how we make sure we can get the 5 years out of it! lol

 John,

Nice job on the roof cleaning you got a bonus day for sure! 

Thanks Jason

Nice job John!!!

Thanks Mike.

Brandon Vaughn wrote:

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I add up to 1.5 gallons of Green Wash per 100 gallons of roof mix with the heavy moss up here.

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Isn't that expensive? Can you buy it by the barrel?