mps shock

[Slappy]

I have been shocking my tub once a week, just as the instructions say on the bottle of "Renew".
they say to add 2 oz. of this to the tub. this seems a bit high as I read that others here only add tablespoons of
this. also, I have to wonder if it's best to shock the tub when the chlorine level is low (around 1) or  
to do it when the chlorine reading is high (3-5 ppm).
Anyone have preferences on this?

-Slappy

[svspa]

slappy,

The good thing is using MPS as your shock you don't have to reach a certain level to have an effect, like reaching the breakpoint chlorination level for a dichlor shock.

So using less would just not oxidize as much of your CC and contaminants, but it would oxidize some.

Seems like there's no harm in trying different amounts until you find the lowest level that does the job.

Remember though you should be willing to increase it if you have more than normal use or go longer between shocks. You might build up more CC and contaminants and should increase the MPS dose accordingly.

Steve

[hottubdan]

The chemical companies really do recommend the proper amounts.

There are actually industry standards

[anne]

I use 2 oz every other week. That is the same as 4 TBSP. Bottle says 2 oz for tubs up to 500 gal, so that is what i do.

[tileman]

I use 2 oz every other week. That is the same as 4 TBSP. Bottle says 2 oz for tubs up to 500 gal, so that is what i do.

My Renew bottle says 2 oz per 250 gallons.

[svspa]

dan,

My only comment is that what the mfr recommends cannot suit every situation. They may recommend 2oz every week. What if I don't use my tub that week at all. Do I still blindly dump 2oz of MPS in? What if I am 1 person using my tub once a week versus someone who has 6 people in their tub everyday.

The question was can slappy learn what his tub really needs and use only that amount when it is necessary. My answer to that question would be yes. Just like I adjust my dichlor use, or PH increaser, or clarifier to what my tub requires, I adjust my MPS use as well.

Steve

[tony]

I have been shocking my tub once a week, just as the instructions say on the bottle of "Renew".
they say to add 2 oz. of this to the tub. this seems a bit high as I read that others here only add tablespoons of
this. also, I have to wonder if it's best to shock the tub when the chlorine level is low (around 1) or  
to do it when the chlorine reading is high (3-5 ppm).
Anyone have preferences on this?

-Slappy

Renew is a buffered non chlorine shock meaning it is pH neutral.  You will use approximately twice the amount of buffered shock than non buffered shock.  I find it much more economical to use a non buffered shock and add baking soda or spa up, which is relatively inexpensive, when I need it.

[tileman]

Renew is a buffered non chlorine shock meaning it is pH neutral.  You will use approximately twice the amount of buffered shock than non buffered shock.  I find it much more economical to use a non buffered shock and add baking soda or spa up, which is relatively inexpensive, when I need it.

It might be cheaper but I think once you add the other chems to bring ph back up you'll have added almost an equal amount of stuff to your water.

[tony]

It might be cheaper but I think once you add the other chems to bring ph back up you'll have added almost an equal amount of stuff to your water.

My experience with my water is that I don't need to adjust pH every time I shock.  I adjust maybe once per month and generally one tablespoon of baking soda brings it in line.

[svspa]

my experience is similar to tony's, I rarely have to adjust PH. once a month or even every other month.

Steve

[wmccall]

I have been shocking my tub once a week, just as the instructions say on the bottle of "Renew".
they say to add 2 oz. of this to the tub. this seems a bit high
-Slappy

Renew is buffered so it doesn't affect your PH, that is why you have to add so much. If you look on the bottle, I think its nearly or more than 50% inert ingriedience.  I use Seaklear, which isn't buffered so I only have to add about 1/3rd as much, but I check the Ph the day after using it.

[tileman]

Renew is 32.25% potassium peroxymonosulfate and 3.26% active oxygen, while Seaklear is 45.2% and 4.3-4.75%.