Potassium Monopersulfate shock

[halds]

I know this probably has been debated ad nauseum, but I could not find anything in the archives.

Could someone review the relative advantages and disadvantages of chlorine vs Potassium Monopersulfate for shocking?

I can guess that cost is a big factor, but Im thinking in terms of effectiveness, effects on pH, etc.

The problem I run into with chlorine is
1. having to lug gallons and gallons of bleach.
2. getting cloudy water with Ca hypochlor
3. Adding too much CYA with dichlor

what are the negs of Monopersulfate?

Hal

[waterbear]

Disadvantages of MPS shock:
1 it is expen$ive
2 it is only an oxidizer and not a sanitizer
3 it will show up as CC on a DPD or FAS-DPD test unless you use a special test kit (additional expen$e)
4 it can convert chloramines to nitrates which are algae food
5 it is expen$ive
6 see number 4!
7 it seems to work better with bromine than chlorine (but chlorine is STILL a better shock for bromine)
8 see number 2
9 it is expen$ive
10 see number 3

Advantages of MPS Shock:
1 They have cute names like Oxy-Brite, Blitz, and Renew

[Rangeball]

I used PMPS last year. 2 bags each sunday for my 22,200 gallon pool.

It worked great. Bought it before I found this place.

Looking at the $ this year, it will cost me $9.50 to shock with 6% liquid bleach (cheapest I can buy locally) or $5 with PMPS.

As long as I keep the FC up with the bleach, PMPS seems to work well.

[halds]

Well lets see, two opposing views, but I might be more inclined to side with Rangeball on this one...

waterbear wrote......

Disadvantages of MPS shock?:
1 it is expen$ive ---------becoming a nonissue with the rising cost of bleach

2 it is only an oxidizer and not a sanitizer----- already a nonissue because I am talking about shocking not sanitizing, naturally one would use chlorine for day to day sanitizing

3 it will show up as CC on a DPD or FAS-DPD test unless you use a special test kit (additional expen$e) --- this is a valid issue, but once I convert over to the other test procedure, costs should be about the same?

4 it can convert chloramines to nitrates which are algae food---- this is somehting that I do not know much about, nor have heard any convincing discussion one way or the other. If there is good evidence that PMPS increases the likelihood of algae formation, I would like the opportunity to read about it.

5 it is expen$ive------ get over it already.....

6 see number 4!---------ditto

7 it seems to work better with bromine than chlorine (but chlorine is STILL a better shock for bromine)--- probably but again a nonissue here....who uses bromine in their pool?

8, 9, 10, ------did that add anything to your argument?


Hal

[DerekM]

Other advantages of MPS:
1-Doesn't elevate the Chlorine level, which means you can swim almost immediately afterward, without bleaching your suit.
2-Saves energy and cuts evaporation and Chlorine use, as you can put your solar cover on immediately afterward, without having its life shortened by high chlorine.
3-No effect on PH (at least that I can see) or calcium.
4-No bleached or faded liners or bathing suits, or white spots on clothing from splashed bleach.
5-No premixing needed (unlike cal-hypo)
6-Instant water sparkle when company is coming!

[waterbear]

Well lets see, two opposing views, but I might be more inclined to side with Rangeball on this one...

waterbear wrote......

Disadvantages of MPS shock?:
1 it is expen$ive ---------becoming a nonissue with the rising cost of bleach
MPS is more expensive than Cal Hypo for equivalent usage amounts

2 it is only an oxidizer and not a sanitizer----- already a nonissue because I am talking about shocking not sanitizing, naturally one would use chlorine for day to day sanitizing
Not really, shocking is part of the sanitizing process. MPS ideally should burn off organics before they become chloramines, in real life you shock after you have CC....see 4 for when they have become chloramines.
3 it will show up as CC on a DPD or FAS-DPD test unless you use a special test kit (additional expen$e) --- this is a valid issue, but once I convert over to the other test procedure, costs should be about the same?
you need an ADDITIONAL test plus what you are already using. Talor lists theirs on their website at $18.95 plus shipping
4 it can convert chloramines to nitrates which are algae food---- this is somehting that I do not know much about, nor have heard any convincing discussion one way or the other. If there is good evidence that PMPS increases the likelihood of algae formation, I would like the opportunity to read about it.
Is Ben (PoolDoc) a good enough source? Check out http://www.poolsolutions.com/tips/tip38.html
5 it is expen$ive------ get over it already.....

6 see number 4!---------ditto

7 it seems to work better with bromine than chlorine (but chlorine is STILL a better shock for bromine)--- probably but again a nonissue here....who uses bromine in their pool?
Bromine is often used for indoor pools where it can have some advantages.
8, 9, 10, ------did that add anything to your argument?


Hal

Hope this clears things up

[halds]

Thanks for clarifying your position waterbear.

However,


I would not let price difference between PMPS and Cal Hypo influence my decision..why? Becasue cal hypo has a really bad tendency to make my pool water cloudy. Something that then takes more money for me to remedy.

I do not want to mince words over the meaning of shocking and sanitizing, so I will give you credit for that.

The rather small additional cost of the kit should not be a determining factor if convenience is a major gain....

Please no offense to Ben, I worship the guy, BUT, that page states that PMPS APPARENTLY coverts some chloramine to nitrates. It does not state that the shock actually increases your chances of getting an algae bloom. As I stated, I would like to hear about tesimonials or tests where poeple have compared the two and actually found PMPS to be algae prone. If Ben has the proof, please share it with us. How much nitrate is formed? Is it an amount that has significant effects on algae? If this were a real problem, it would be major headlines by now? I am not trying to be argumentative, but on the other hand, I am not going to jump to a conclusion that PMPS is bad based upon a concern that has not been proven, if it has, that is what I am asking to see.

And please I am just trying to have an informed discussion here. Not to prove you wrong.

[waterbear]

I realize that you are trying to have a discussion. I can also tell you this from my own experiences. I used to have a large portable spa that I ran on bromine for several years. I had all sorts of problems when I used MPS for shocking (algae blooms and cloudy water) and they stopped when I started shocking with bleach (don't know for sure but I think the bleach is more effecient at reactivating the bromine bank).
I also work in a pool store. I test water all day and tell people what to put into their pools. I recently had several customers that were having problems with cloudy water and algae that were using MPS. (It generates more revenue for the store and is recommended often by some of the employees) I suggested they try sodium hypochlorite or cal hypo for shocking and EVERY ONE OF THEM came back and told me that the problems stopped when they switched and have not returned so far. I know that is not proof but it is in line with my personal experience also.

There is has also been some discussion that I have seen on DuPont Oxone (this is what mps shock is) that it might not be safe to swim right after application. the jury seems to be out on this one yet.

Also, right on the DuPont website
http://www.dupont.com/oxone/index.html
they state that it needs to be used as a preventive maintenance before chloramine form and that is will oxidize only nonmicrobial contaminents, they state that it will not effectively reduce chloramines (breakpoint chlorination is required for that), and that it is not as an effective oxidizer as chlorine.
They aslo state that it can lower pH and TA!

It also introduces sulfites and sulfates into the water and there has been some discussion on this forum in the past on how these can have adverse effects on plaster pools.

IMHO, MPS is a good choice for an indoor pool to help eliminate some of the problems that occur but for an outdoor pool it really has no benifits.

[halds]

Thanks waterbear,

Your experience and info is very helpful.

Hal