MPS Causing Itchy / red skin

[navman]

I have a Hot Springs Envoy NXT tub.

The last few years I have been getting itchy / red skin after using the tub, usually noticeable the next day after using the hot tub I use a Nature 2 Spa Sanitizer, last year I used Chlorine, this year I switched to Bromine to isolate the issue.

I use a public hot tub and no issues with that or any other hot tub just my tub at home.

I have been using Zodiac Cense MPS Spa Hot Tub Shock & Aromatherapy  a few times a week,  after much investigation I have determined that this is the root cause of my issue.

My tub was last drained three months ago, I could do this again if absolutely required, is there anything I could add to bring down the effects of the MPS  immediately?

Any tips or advice would be greatly appreciated.

 

 

 

[RDspaguy]

Most skin irritation in a hot tub is the result of ph and alkalinity. Chlorine, bromine, mps all affect ph balance. Continuous feed systems, such as floaters, inline feeders, tablets in the filter well, and such will cause a continuous drag on the ph that is difficult to counter with once-a-week balancing. Mps is high alkalinity, and is a generally inaccurate treatment, the amounts used having no direct correlation with the levels of chloramines in the water. 

I know of no way to remove mps except to drain it. 

In my tub, I use 1 tsp dichlor plus 1/2 tsp per user after each use. Adjust ph and alk as needed, which is seldom since dichlor is ph neutral. I also shock with dichlor if my test says I need to shock. Most of my shocking is done when I add my dichlor after use. I have ozone to dissipate chlorine, and enjoy clear, virtually chemical free water when I open my cover. 

This is the system I recommend to my customers as well, I have no complaints. I advise that you try it.

[navman]

Hi thanks for the info.

I assume you mean Dichlor sanitizing granules,  should these be used in conjunction with the nature 2 Spa sanitizer?

I have refilled my tub and added Chlorine and an Oxidiser..... moving forward should I only be adding Dichlor on a regular basis?

[RDspaguy]

An oxidizer? What oxidizer, exactly?

Nature 2 uses silver and copper to inhibit bacterial and algea growth in the water, much like an algeacide in a pool. It is compatible with dichlor.

Balance alkalinity and ph and add 4 tsp dichlor at fill up.

Add 1tsp plus 1/2 tsp per user after each use. Leave cover open for 30 minutes after.

Test balance and chlorine weekly, looking for combined chlorine. Shock with dichlor if needed. Mine is always good, but I have ozone burning off my chlorine and chloramines.

I hope this helps. Enjoy!

[navman]

Hot Springs MPS Spa Shock - (Oxidiser)  I added this yesterday two hours after Chlorine.

My  local spa guy told me to do this.  Moving forward I will use Dichlor to maintain, does that sound good?

 

 

[RDspaguy]

You can use mps to shock, just be aware of what it is doing to your balance. Has a very high alkalinity. I prefer to shock with chlorine because I know exactly how much to use based upon the current water conditions, and dichlor is nearly neutral in ph so it does not mess up my balance.

[navman]

Hey guys I am needing to refill my 390 gallon tub this weekend, still getting itchy rash next day - it is currently draining and I will refill later today.

In order to get this right please provide some guidance what I should add at the start and how to maintain I will then use tests trips to maintain PH and Alkalinity.

Once Tub is filled to desired level what should i add out of following and after what duration

• Nature 2 Spa Sanitizer, was replaced two weeks ago, should be good to continue to use.
• Chlorine - How much should I add and when? Should I run a clean cycle and if so for how long?
• Shock - I have MPS Spa Shock and have ordered Dicholor (arrives tomorrow), how much should I add and when ?  Clean cycle for how long?

Testing

• I understand that ALK levels need to be 40-120 PPM and PH 7.2 - 7.8,  I can use test strips with PH up / down to maintain, any other tips?
• TBR and FCI I understand these should be 3-5, will my test strips reflect that soon after adding these chemicals?
• Hard water - what can I do to bring this down?

Any other tips would be greatly appreciated.

 

 

 

[RDspaguy]

Leave out the nature 2.

Fill spa. Test alkalinity.

Balance alkalinity to 80 to 120ppm , 100 being ideal.

After alkalinity is adjusted and stable, at least 24 hours, test ph.

Adjust ph 7.4 to 7.6.

You should not have a chlorine or bromine reading in your spa except right after you add chlorine. Which should only be dichlor. Do not add liquid chlorine or any type of tablet. You are not concerned with what that reading is for now. 3-5 ppm is health dept requirement for PUBLIC spa. Unless you have constant use by everyone in the neighborhood, YOU DO NOT NEED THIS, it is only causing problems.

Add 4 tsp of dichlor only AFTER ALK AND PH ARE BALANCED. 

Use it and enjoy. After each use add 1tsp plus 1/2 tsp per person in the spa of dichlor. Leave cover open for 30 minutes after to help prolong your cover life.

Once each week check alk and ph, balance as needed. Check free cl and total cl, and shock as needed with dichlor. If free cl and total cl are the same or zero, you do not need to shock.

You may add the nature 2 stick whenever you choose. I would leave it out for now to help eliminate it as a source for your discomfort.

Rinse filters monthly. Clean them throughly every 3 to 6 months. Drain and refill yearly.

Do not use other chemicals. Scents, mps, conditioner, ph stabilizer, foam remover, none! 

To avoid foaming, do not wash your suit in soap and fabric softener. Do not get oil, lotion, hair conditioner or makeup in the water.

Hard water, meaning high calcium, is not feasible to reduce. Keep your alkalinity where it belongs and your hard water will not be a problem. If alk is high, calcium will come out of solution causing a sandpaper feel and white staining in your tub.

A "clean cycle" just moves water through the filter and runs your ozone if you have it. It is meaningless to your spa maintenance. Filter cycles are what count. You want at least 2 hours twice per day minimum! Run a clean cycle after you add chemicals or before use if you like.

[navman]

Hi there,

Many thanks for the quick response .

Couple of follow up questions:

 

• You have advised to balance the Alkalinity before PH, to be clear use the same substance to reduce Alkalinity and PH, I am assuming if PH needs to be increased it is a different substance that is used to raise Alkalinity?
• Basically I can use my tub for first few days without adding any chemicals, (once Alkalillity is stable) then I maintain with Dichlor moving forward.
• Can the Sanitisier cause any skin issues / rash etc?

[RDspaguy]

It is a slightly different chemical. Ph and alkalinity are opposite sides of the same coin, and one always affects the other. Think of alkalinity as a ph stabilizer. If it is low, a gnat fart will change your ph. If it is high, nothing will change your ph and dissolved solids will come out of solution all over your spa. It takes a signifacant amount of chemical to affect your alkalinity, but very little to affect your ph. Do your alkalinity first or your ph twice, I always say.

I would get alkalinity and ph in line, then add 4tsp dichlor and wait several hours before use. Initial balance is crucial, if you get it wrong you will fight it every week. Take your time and you only do it once a year. If you use the tub, you bring contaminants into the water that must be sanitized or they will multiply and create an unhealthy spa environment. Do not use the tub until you are ready to use dichlor, which is after your alk and ph are balanced and stable.

Very rarely, and I mean VERY, people can have a reaction to chlorine or bromine. These people will also react to chlorine bleach, household cleaners, and such. They will not discover their chemical sensitivity by using a spa. Most issues of water irritation are ph related. Even if chlorine causes the ph issue, it is ph, not chlorine, that irritates your skin. Excessive levels of chlorine or chloramines can cause dryness, which in turn causes irritation. I have also heard of mps sensitivity, but can't say if it is also being misunderstood, as mps has a high ph and affects your test chemicals, making accurate readings problematic.

[navman]

Thanks for the tips;

I have filled spa with water, I have ran a test strip, as expected PH and Alkalinity are high.Alkalinity is around 220 to 240 PPM.

• I have added 8 OZ sodium bisulfate and ran a clean cycle.
• I will wait 18-20 hours before testing again, once this is desirable I will work on the PH.
• Once PH and Alkalinity are as desired I will add 4 TSP Diclor and run a clean cycle.
• Wait 4-6 hours before using the spa at least.
• I will Maintain with Diclor on a regular basis as per instructions, no need for Oxidiser or Chlorine to be added.

Once everything is as desired I will re-introduce the sanitizer, does all that sound good?

[RDspaguy]

Re-introduce what sanitizer?

Dichlor is a form of chlorine and the only sanitizer or shock that you need. Use it as I instructed. 

Nature 2 is a mineral purifier, which is a meaningless term. Sanitizers, by code, must kill organic contaminants. Purifier does not appear in the health code. Nature 2 is a glorified algeacide, which helps with sanitization and water clarity, but it is not a sanitizer. If you are having skin irritation issues with your spa, leave it out at least until you know if your irritation stops. If you use the spa trouble free for a few weeks, then reintroduce it and start itching, you will know.

[navman]

Thank you for all the tips much appreciated.,

One more question in regards to this bit of advice: 

If free cl and total cl are the same or zero, you do not need to shock.

My test strip only shows FCI (Free  Chlorine PPM) or TBR, how do I validate total CL?

Also if the results are not the same how much Diclor should you add to shock?

[RDspaguy]

Get test strips for free and total cl.

Tha amount of shock you use is determined by the difference between free and total cl. As a rule of thumb, I use 4tsp dichlor. If you have an ozonator you will rarely need to shock. Under normal bather load, you will not need to shock with this method as you are basically shocking after each use.