How long does fresh SH last before it starts to degrade

So does anyone know about how long SH will last before it starts to degrade? I had a barrel delivered yesterday morning for a roof cleaning I was supposed to do today then my client had to reschedule to the beginning of next month. Will it hold its potency for 2-3 weeks. The company won’t take it back and the rest of my month is billed with window jobs so I really have no use for it until then. It’s in the shade in a black barrel so is protected from the sun.

@CaCO3Girl … This seems to be right you your alley. :grinning:

It’ll be fine. May have to bump mix slightly.


Okay. I’ll take your word for it. Thank you.

Thanks for alerting me.

There are three things that degrade SH the fastest:

  1. Sun (you have that covered)
  2. Heat (I wouldn’t go over 80)
  3. Air (so leave it capped, but check on it in case you had “special” people pack it and they didn’t use a vented cap…if you see it bowing up open the cap 1-2 times a day for 5 minutes)

We keep SH for about a month, but it starts to degrade right after production. This happens so often I test the chloride content when we receive it. If it’s not at least 12 I return it, but I’ve gotten as low as 9. The good news is that even at 9 it will do it’s job, but not as fast.

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Thank you. :pray:

Luckily there are several suppliers near me . Between. .93c to 1.07 that doesn’t sound like much but obviously I want it as cheap as possible. The place for .93 has two 1800 gallon tanks and only fills them every few weeks when the get low. The place for 1.07 only has one tank and is more established there tank gets topped off twice a week . The difference in strength is night and day . Several times I couldn’t figure out why I was having to treat a roof so many times before it cam clean then I realized it only happens when I get it from the cheap place . These tanks are outside / in the sun / well over 95 degrees out and the tanks are clear and vented. In these conditions 1 week kills the chem


Good to know.

I once tried to test my SH with my pool test kit. Should work in theory, right? Then I realized I’d have to dilute a quarter teaspoon of SH with 100 gallons of water. Something crazy like that.

What can be used to test it and where can a tester be purchased


When I get to the lab tomorrow I’ll write out my chloride test. It’s just a few reagents and a scale, nothing high tech needed. If I forget someone please remind me by @CaCO3Girl me as was done above to get my attention.


Dude, like you would want to swim in 12.5 SH :joy::joy::joy::joy::joy::joy::joy::joy::joy::joy::joy::joy::joy::joy::joy:

To test for SH content:

What you will need:

  1. A scale capable of measuring around 150 grams

  2. A 250mL Elenmeyer flask (this is the one with the skinny neck and the big base)

  3. Potassium Iodide (KI) Solution, 40g/L

  4. Hydrochloric Acid (HCl), 1 N (That’s one NORMAL for the nonscientific folks)

  5. Sodium Thiosulfate, 1 N

  6. Distilled water, is sold at your grocery store, DI would also be okay.

  7. Glacial acetic acid (you know this as white vinegar)

  8. Put the flask on the scale, set to zero by taring it.

  9. Add in 1.8 - 2.0 grams of the SH into the flask

  10. Record number as weight of SH

  11. Add around 50mL of Distilled water and 3-4 grams of potassium iodine solution to the flask. (The solution will turn a red brown from the Iodine releasing)

  12. Stir by swishing around the flask

  13. Add 3 mls of glacial acetic acid (if using white vinegar add 10mls)

  14. Stir by swishing around the flask

  15. Weight the beaker, tare to zero

  16. While stirring add in the 1.0 Normal sodium Thiosulfate. When the color becomes a light tan, start to be much slower on your addition rate. The endpoint occurs when the solution changes from a yellow to colorless liquid.

  17. When you get a clear liquid wait one minute, if it’s still colorless then weigh it again and see how much Sodium Thiosulfate you added.

  18. That number is called the volume of sodium Thiosulfate used (even though we weighed it it should still be about the same)


   (Volume of Sodium Thiosulfate) x 1.0 (which is the normality) x (3.722)
                                           Sample weight of the sodium hypochlorite

Okay, who has questions???


There is supposed to be a number break between 7 and 8 but I guess it just kept numbering rolling my eyes

How many grams? Looks more like an IP address, lol.

So if I’m following this right, you’re basically trying to get all the chlorine to evaporate out of the solution, so that you can measure how much was in there to begin with. Or am I way off base (pun intended :smirk:)?


I have a question. Is there an easier way? I can follow instructions and do basic math but if that’s the only way I’ll just keep on guessing.

Product idea: if I could just dip a test strip in my sh that would be great. You should invent it. People will be lining up to buy some.


Yeah the formatting didn’t exactly transfer correctly.

1.8. - 2.0 grams

This test is to see how much of the potassium iodide reacted. It reacts based on how much cloride was in the product.


I usually test by feel, smell, and taste lol.


That explains SOOOOO much man! Thanks for sharing!:joy: