MPS vs. Dichlor?

[kellpup2112]

My wife and I have an eight month old Caldera Geneva that we enjoy daily. I've had very few problems keeping the water clean. The tub has an ozonator and uses a Monarch silver ion cartridge. I've followed the routine provided by my dealer which includes dichlor after each use, a weekly shock with MPS, and weekly addition of stain and scale(we have very hard water in San Antonio). I also soak my filter in cleaner monthly and rinse it very thoroughly.   The problem we're having occurs when we add air to the jets. The water becomes very "fizzy" and the mist causes us to cough until we turn the air off. After researching here, I've come to the conclusion that the problem is caused by the MPS.
I just did a water change two days ago. My start-up procedure includes a dichlor shock, but no MPS until a week later.  The "fizzy" problem in nonexistent right now, so I'm contemplating dropping the MPS altogether.
Do any of you chemical experts out there see any problems with this? I've reviewed my owner's manuel and the directions that came with the silver cartridge. Everything says to use MPS OR dichlor, but also says that the MPS activates the silver ions. Does that mean that without MPS the siver cartridge won't work? Any advice would be greatly appreciated. We really enjoy the air with the jets, but not the cough.

[svspa]

kellpup,

If you want to drop the MPS you would still need something to 'shock' the tub on a regular basis.

Shocking removes the chlorine that has killed bacteria (called combined chlorines). Combined chlorines do not have any sanitizing ability and can interfere with new chlorine you add to the tub. So you gotta get them out of there.

You can use chlorine to shock, but it's a big dose (about 7x your normal dose). Which means you cannot use the tub for probably 1 day after giving it a chlorine shock.

I use dichlor daily, MPS for my weekly shock and about once a month I replace the MPS shock with a chlorine shock. An added benefit of the chlorine shock is a super sanitizing effect on the tub.

Check out this link for Northman's and Vermonter's recommendations on dichlor dosing a hot tub. There is a lot of good info in there. Look for their names in the list of FAQs.

[link]http://www.rhtubs.com/cgi-bin/bbs/config.pl[/link]

I believe you can use only chlorine with the N2 cartridge. I used an N2 cartridge for awhile decided to try without it, actually haven't seen any difference in my water. Just my experience.

I am sure others will reply and give you good info on this subject.

Steve

[Brewman]

I'd also check your readings on alkalinity and Ph.
I've heard that too high can result in fizzy water and coughing.

[kellpup2112]

Thanks for the input guys.  Brewman, what you say about high Ph and alkalinity makes sense, but in my case I'm not sure that's the cause. Because of our hard water, they are fairly high. My dealer told me not to worry too much about lowering them. He said that with weekly use of stain & scale, the tub would suffer no ill effects. (Does that sound reasonable?) He also said that with usage, both would drop, and I have found that they do. But the fizziness and coughing aren't there with fresh water and have always gotten worse the longer the water has been in use.

[Vinny]

Nature 2 (N2) says to use dichlor to start the reaction and MPS or dichlor for the cleaning and shocking. I don't know about other brands but I would imagine it's probably the same.

As far as fizzy water, I don't recall reading that MPS is the culprit. I do know as water gets older it does change the way it behaves in the tub. My tub gets fizzy within a couple of weeks of a water change, I just assumed it's normal. Unfortunatley, I can't remember if I used MPS or not before it became fizzy.

Personally I try to use dichlor for everything except when I get a high combined chlorine (above 0.5 PPM) or get foam. The MPS destroys the  combined chlorine without the higher chlorine needed to break it and the combo of chlorine and MPS does a great job of eliminating whatever is causing the foam.

I vote for trying this water change without the MPS and see how you make out.

[marks]

I use Nature 2 and Dichlor only and it works like a charm.  I use Dichlor after use and shock once a week with it.

I have also read that when using Bromine a weekly shock of MPS turns ineffective bromides back into active hypobromous acid.  So MPS may be better for Bromine?

[hottubdan]

How old is the water when it starts fizzing?

[kellpup2112]

Hard to say, maybe a month or a month and a half, which Is why I'm thinking MPS may be the culprit. Maybe it builds up after a month of weekly shocks? When it fizzes there is a distinctive smell, kind of a clean smell, but whatever it is, it causes us to cough.

[Brewman]

Next water change, skip the MPS and just shock with dichlor, and see if it keeps the fizzyness at bay.
But do keep an eye on your Ph and alk levels, some chemicals work best in a certain Ph range.

[Gomboman]

Many people here are on the same regiment as yourself without any problems. I typically shock with dichlor though.

Have you had your water professionally tested? Maybe your dealer can help. I would dump out the water and substitute dichlor for MPS to see if things get better for you. Let us know how it turns out.  

[kellpup2112]

The concensus here seems to be that I should go without MPS, shock instead with dichlor, and see if it helps. That's the plan. Thanks for all the help and I will let ya'll know how it comes out. Sure hope it works. We can deal with the fizziness, but not the coughing. I changed water Sunday, and so far so good, but it's way too early to draw any conclusions.

[drewstar]

The Shocking once a week is more a rule of thumb.  I shock with MPS  maybe every 14 days.

I have a 350 gal tub with cd ozinator and use dichlor after each use.  The tub is used about 3-4 times a week at most.

My dealer recomeded cutting back on the shocking and I have not had a problem.

[Bill_Stevenson]

First of all the advice to look at the Vermonter's and Northman's recommendations is highly endorsed by me.  Second, adding MPS for shock is OK, but it does add to the total dissolved solids (TDS) more than would be the case with  using dichlor.  You might want to test for TDS and watch for the point where the fizzy deal gets to be a problem.  That amount of TDS might be the water change point for you.  Everyone uses their tub differently and everyone will have slight variations in their water.  That is why it is important to measure the variables.  Having your water tested at the shop where you buy your chemicals is also good advice.

MPS is an oxidizer and it burns up a lot of intermediates that get into your water besides just eliminating the chloramines (i.e. combined chlorine ions).  I use it very little, but I change my water every 60 days or so.  With that said, after a long weekend of company I had foaming (probably from bathing suits or soap on skin or both) and used a half cup of MPS to burn it all up.  So, having some MPS on hand can be useful occassionally, but for daily and weekly use, dichlor is all you need.  

The advice to use 7x the dichlor used daily for shock is overkill.  See the Vermonter's info for clarification as this was his original recommendation.  5x is probably more like it.  Also, I don't agree that after shocking with dichlor you have to stay out of your tub for a day.  I shock at night after use, and do not hestitate to use the tub again the next evening even if the residual chlorine is still somewhat high ( ~ 5 - 7 ppm).  

Regards,

Bill

[tony]

I don't believe the fizziness is being caused by the MPS, but more the age of the water and TDS.  I also am one not to shock until needed (total chlorine > free chlorine) which maybe anywhere from one to four weeks.  I have also used only dichlor to shock for over a year, but I am back to and prefer shocking with MPS.

From what I understand, you don't need MPS to "activate" a sliver ion cartridge.  Just install the cartridge and add your dichlor.

[kellpup2112]

Update: 3 weeks into my new water without using any MPS, the fizziness is back but not the coughing. The water has remained crystal clear using dichlor to sanitize daily and shock weekly. The only other additions to the water are weekly stain and scale, and a little inSPAration, which the wife just can't live without.