Old topic, but good information about BLEACH

Pete Marentay

Distinguished Professors
I have really missed teachin' and preachin' like in the old days, so I thought I'd like to chime in on something.

In the world of cleaning and sanitizing, bleach has been a “go to” product for years.

Many people have asked me about using industrial bleach and its advantages over bleach bought at the grocery store or Clorox Outdoor. The answer has always been that bleach is essentially the same in any form and only the concentration changes.

Grocery store bleach used to average around 5.75% concentration Today you can buy more concentrated bleach in the grocery stores that delivers around 7.5% as well. You have to read the label carefully, but seeing words like “33% stronger” and “super concentrated” are a good tip-off to the stronger concentration. Industrial bleach is rated between 12% and 15% concentration and Clorox Outdoor averages around 7.5% concentration.

Why do so many contractors prefer industrial bleach? The triple cost advantage to using bleach at that concentration is huge. Let me share some examples. We will start with the cost of buying the bleach.

Suppose you wanted to clean a house using 5.75% bleach. If your goal is to use a final concentration of 1%, which is typically strong enough for killing the mold and algae if combined with a good detergent that delivers some cling, then each gallon of bleach can be cut with 4.75 gallons of water – creating 5.75 gallons of 1% bleach.

If you start with 7.5% bleach, then each gallon can be cut with 6.5 gallons of water to get the same killing power (notice I didn’t say “cleaning power” because bleach doesn’t clean, it sanitizes).

If you pay $3 for the 5.75% bleach and $10 for the 7.5% bleach, then the $5.75% bleach cost you $0.52 per usable gallon. The 7.5% bleach actually cost you $0.75 per usable gallon – over-priced a bit.

Using 12.5% bleach, which many contractors can buy in bulk for around $3.50 per gallon actually delivers 12.5 gallons of usable 1% liquid for about $0.28 per usable gallon. The savings are obvious.

The second part of lower costs using industrial bleach is the cost of transportation. A gallon of 5.75% bleach weighs the same as a gallon of 12.5% industrial bleach, so you can haul less than half of the amount of bleach to get the same amount of power. That translates into more MPG and fewer brake pad changes over time. It can even mean using a smaller truck since you carry less weight, but most won’t count that as a real saving.

The third element of savings comes into play when you need volume for your work. You are limited to carrying about 115 gallons of bleach at a time by DOT regulations – NO MATTER WHAT CONCENTRATION THAT BLEACH IS. That means that you can carry 115 gallons of 12.5% bleach instead of 115 gallons of 5.75% bleach and get more than twice the bleach power. This is very important to contractors who clean roofs, for example.

In the end, nothing beats the economy of using industrial bleach. This is great information for the guys who can get their hands on the stuff, but what about the guys who cannot? Well, remember where we started out? All bleach is the pretty much the same except for the concentration. So if your only source of bleach is laundry bleach, go to Wal-Mart or some store where the bleach moves fast and is always fresh and use that. You can kill just as many germs or just as much mold – it just takes twice as much and will cost you twice as much per gallon. In the big scheme of life, the difference for most house wash jobs comes down to a few dollars on a $250 job, so don’t sweat the little things.

Next, take care of your bleach. Keep it out of sunlight and away from excessive heat. Bleach is pretty unstable and will break down fast enough without sunlight and heat, but adding sunlight and heat can affect bleach – and lower its effectiveness – in just a few hours. Learn from this and only buy enough bleach at one time that you will use in a week or two. Hold on to bleach longer that, and its performance drops dramatically. A lot of people think their soap isn’t working right when the truth is they are trying to use stale bleach. Just like fresh gas, fresh bleach packs the punch and stale bleach does not.

PS – Watch out when you buy bleach in a local store. Most bleach is sold in containers that look like gallons but really aren’t. Some are as small as 3 quarts. Be sure to check the size of the jug when you are mixing cleaners and when you are calculating costs.

PPS – why is Clorox Outdoor so expensive? Simply put, Clorox Outdoor is formulated a little differently for several reasons. One of the primary reasons is that it moves a lot slower off the shelf because it is perceived as a specialty product. They formulate it with a small amount of sodium hydroxide to keep it a little more stable that ordinary bleach (which is incredibly unstable and can go bad in 30 days or less). Clorox Outdoor is sold in home improvement stores and hardware stores instead of grocery stores, and that affects the price too. Now that you can get 7.5% bleach in grocery stores, Clorox Outdoor doesn’t really seem worth the cost for a contractor.
 
Great info Pete!

Good to see you around PWI.
 
If your goal is to use a final concentration of 1%, which is typically strong enough for killing the mold and algae if combined with a good detergent that delivers some cling, then each gallon of bleach can be cut with 4.75 gallons of water – creating 5.75 gallons of 1% bleach.

No offense, but that makes absolutely no sense at all and the math is completely wrong. These people think you are right when in fact you are not.

1 gal of bleach = 128 ounces, plus 4.75 gals of water (608 ounces) = 5.75 gals of mix, which totals 736 ounces. 1% of that mix would be 7.36 ounces of bleach (not 128).

To make a 1% concentration you need to mix 1 gal of bleach with 99 gals of water. The mix you describe (1:4.75) is approximately 17% solution.
 
Hess talking about the percentages of sh.. as in 12% cut 50/50 would be 6% available sodium hypo

That makes even less sense. 12% bleach cut with water is still 12% bleach PLUS the water. 50/50 (bleach/water) is 50% (12% bleach) and 50% water.

Cutting the volume in half does not cut the concentration in half. By your logic, if I put 2 gals of 7.5% and 2 gals of water together I will have 15% SH.

Simply put, the concentration (7.5%, 10%, 12.5%) doesn't change, only the ratio to water changes. 1 gal of SH + 1 gal of water = 50% SH, not 50% of the concentration.

Put another way, there's less SH, not a weaker SH. 1 gal of SH = 100% (SH). 1 gal of SH + 1 gal water = 50% SH + 50% water.


Unless of course, water breaks down SH, and in my opinion that would be a bad thing.
 
Sorry that you aren't getting it, Red. Cutting 12% bleach 1:1 makes it 6% bleach. Water doesn't harm bleach, it simply dilutes it. Weaker bleach is always created by diluting. Cutting it with any liquid would dilute the strength of the sodium hypochlorite to a lower percentage. Simple math.
 
Red, I'm not a seasoned PW'er like a bunch of guys here, but I am VERY good at math.
I don't think you understand the reasoning.
If you have 100 gallons of 10% SH, that means you have for argument's sake 90 gallons of water and 10 gallons of actual SH by volume. If you want one percent SH delivered to the surface you're cleaning you can dilute that by a factor of 10. I'm pretty sure most downstreamers don't get 10:1 (water:10% SH). If you get 5:1, you can make your mix 50% (10% SH) and 50% water.

Adding water most certainly lowers the concentration. If you have your batch of KoolAid just right and your wife adds a bunch of water behind your back, when you drink it or even look at it you'll know the concentration is weaker.
 
Good to see your message, too, Shane. I have family around your part of the world. Maybe when I get out there I will stop in.
 
Good to see your message, too, Shane. I have family around your part of the world. Maybe when I get out there I will stop in.

Sounds good my office is right outside Tomball if you get out this way give me a call.
 
Too true, Kory. I feel bad for the guys who only have access to store bleach. I always advised them to go to Wal-Mart, where people are buying bleach even at 4 AM. I believe they offer the freshest store bleach of anybody, but that is no guarantee that the jugs haven't sat in a warehouse for a while.
 
Red, I'm not a seasoned PW'er like a bunch of guys here, but I am VERY good at math.
I don't think you understand the reasoning.
If you have 100 gallons of 10% SH (I assume you to mean mix), that means you have for argument's sake 90 gallons of water and 10 gallons of actual SH by volume. If you want one percent SH delivered to the surface you're cleaning you can dilute that by a factor of 10. By Diluting the current mix by a factor of 10, that would mean you would have (approximately) 990 gallons of water.

I'm pretty sure most downstreamers don't get 10:1 (water:10% SH). If you get 5:1, you can make your mix 50% (10% SH) and 50% water.

Adding water most certainly lowers the concentration. If you have your batch of KoolAid just right and your wife adds a bunch of water behind your back, when you drink it or even look at it you'll know the concentration is weaker.

Let's swap SH for BB's (just for S&G's). Fill a 1 gallon jug with BB's and now add those BB's to 9 gallons of water. The BB's take up 10% of the total volume. Are you telling me, upon adding the BB's to the water, there are now 90% less BB's in the water? Of course not, that would be silly. The same applies to the strength of the SH (concentration), it is not weakened by dilution, it is just thinned out to cover a greater area. The SH is still 12% (or whatever strength).

Does paint lose any of its qualities when used with paint thinner? No, it just spreads easier and covers more area. 12% SH does not turn into 6% SH when mixed with ANY volume of water. The SH does not get diluted, it gets spread out over a larger area.

The confusion here, in my opinion, is the use of the % symbol. The % of how much SH in the mix is hitting the surface is not the same as the strength % of the SH. The volume of SH is diluted, not the strength.

Hope this makes sense to you (and others) because I have literally measured the volume of SH to water with my DSer. Almost exactly 1 gal of SH is used for ever 4 gals of water. That puts my mix hitting the surface at 20% (SH) and 80% (water). The SH (in my case 10%) hitting the surface is still 10%.

If 1% SH is strong enough to clean a house, then why are we buying the "hottest" SH we can find? Why not just buy 1% and use it straight?
 
Hmmmm...the % after sh refers to "by weight".
So if have 8lbs of any liquid...and it contains 12% duck shiz....totalling a whoaping .96lbs of duck shiz in that 8lbs. If you add 8lbs of duck urine to that mix you then have 16lbs of a duck shiz duck urine and "any liquid" mix...out of that 16lbs you still only have .96lbs of duck shiz...but out of 16lbs its only 6% duck shiz.... .06 x 16=.96
I hope mallard appreciates all this duck talk..lmao
 
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