I had a question about this in my PMs this morn. Thought my response was worth reposting here.

AC

Where did you get your SH and I believe I remember you being in Canada so if you recieved your SH in a 55 gallon drum it is very likely that it degraded signifigantly before you recieved it. Bleach or SH is VERRY much like the drug industry (Miami Vice Days) Drugs come in from Columbia at 100% strength, gets cut by upper line dealer, sold, cut by mid line dealer, sold, cut by bottom line dealer, sold. end user gets 50% drug 50% filler.....lol

Bleach is verry simular except the dealers dont usually cut it (though I have seen this happen and is occasionally common) What typically happens is that it is delivered from the factory in a 3500 gallon stainless steel truck and pumped into storage tanks at the upper line chemical supplier. Then it is usually either loaded into 300 gallon totes or 55 gallon drums and sold to the mid line dealer. Sometimes it gets to the mid line dealer by smaller tanker truck and deposited into their 1500 gallon storage tank. Then the mid line dealer fills 300 gallon totes, 55 gallon drums and or even loads it up into their box truck in a larger tank and delivers it to your local chemical distributor for resale into the local dealers tote, drum and or tank. Usually unless you are buying huge bulk in SH your SH you now have in front of you in your 55 gallon drum has prohably passed through three hands, exposed to agitation, air and sunlight, and has degraded way below the 10% solution strength. The 12% MSDS or label on the container you are getting is merely an element of compliance and not a true representation of the product you recieved.

I wish there was a GOOD way to test the overall strength of the SH. However there is no practical way of accomplishing this. 

I know this when I as Mallard or TerraClean had SH delivered to me it cam directly from Odessy Manufacturing (the bleach plant) in a 3500 gallon stainless steel truck and trailer and was deposited into my 3500 gallon tanks before it was a day old. It was labled at 12% and it would immediately eat a hole in your jeans if you got some on them. If it set in my warehoused, sun and heat protected tanks for 20 days it was easily half as strong as the day it was delivered. It wasnt even repackaged three times!

(in the good ole days we actually went through 30,000 gallons of bleach a month)

A good strong SH will upon exposure to your finger tips foam heavy white, be verry slick to the touch almost like motor oil and have a STRONG bleach smell (knock you over smell) If your SH is not slick feeling when rubbed between your fingers (this is actually not viscosity but actually the effect of you feeling it eat away at your skin) is hot to the touch, has a STRONG smell and foams upon immediate contact, YOU PROPHABLY DONT HAVE FRESH SH. 

Please take this into consideration when mixing your chemicals. 

Hope this helps.

AC