Wife says spa water dries out her skin... Also having trouble maintaining FC

[Wineguy5942]

Just like it says, my wife says that her skin feels dry when we get out of the spa. Here are my current levels:

FC: 5ppm
CC: 0
pH: 7.6
TA: 55
CH: 140
CYA: 45
BOR: ~50

I was wondering if there was an ideal chemistry to shoot for that would be easy on her skin? She uses a lot of lotion normally so her skin is already pretty dry...

Also, I am having a heck of a time keeping the FC up where it belongs. I am doing the dichlor + bleach method. Using a 10% bleach solution that I picked up from Ace Hardware (lists 10% sodium hypochlorite) I am having to put in nearly 6 ounces into 220gal of water after my wife and I get out for there to be any FC the next day. I've never tested above probably 0.5ppm of CC the next day, but the FC level is always down to 3 or 4 or so. Before doing the bleach method I would throw around a tablespoon of dichlor in after we got out and the FC would be at least 6 the next day and would take a couple days of non spa use to come down. Any thoughts?

 

[Newdude]

You are making people soup so the FC loss is to be expected. 2 people in a 220 gallon tub is the same as 318 people in my 35k gallon pool. Let that sink in for a minute....

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If you follow the FC/CYA Levels, there are usuallt no irritations to swimmers and its less harsh than tap water at any CYA level. It sounds like you have been doing well keeping everything sanitary, so good job there. Always listen to your tub, it will not listen to you. Also, always round up the CYA.

For the irritation, try adding salt. It helps for alot of folks. Add 1000 ppm per pool math and see how that feels.

How old is the water ? Once it starts getting away from you it usually means it's time to drain. (3-6 months).

Have you purged the tub with Ahhsome ? Plan on doing so at the next drain.

 

[bredwrd]

The biggest change you mentioned is going from straight dichlor to mainly bleach. I'm guessing your CYA levels were much higher before. CYA has the effect of stabilizing chloring, making it last longer, but at the same time it also decreases the effectiveness of it. It's possible that when you were using mainly dichlor, your CYA levels were high enough to keep the chlorine around for longer, but it wasn't necessarily working very well at keeping the water clean.

Now that you're using mainly bleach (after using dichlor to establish an initial bank of around 30 ppm CYA), you may be a bit behind on sanitizer. I would recommend SLAM-ing the tub for a few days until the chlorine demand dies down. Failing that, and especially if you've been going on this way for some time, I'd purge your tub with Ahh-Some, drain, refill, and SLAM it right away next time you notice yourself not keeping up with the chlorine demand.

 

[Wineguy5942]

The biggest change you mentioned is going from straight dichlor to mainly bleach. I'm guessing your CYA levels were much higher before. CYA has the effect of stabilizing chloring, making it last longer, but at the same time it also decreases the effectiveness of it. It's possible that when you were using mainly dichlor, your CYA levels were high enough to keep the chlorine around for longer, but it wasn't necessarily working very well at keeping the water clean.

Now that you're using mainly bleach (after using dichlor to establish an initial bank of around 30 ppm CYA), you may be a bit behind on sanitizer. I would recommend SLAM-ing the tub for a few days until the chlorine demand dies down. Failing that, and especially if you've been going on this way for some time, I'd purge your tub with Ahh-Some, drain, refill, and SLAM it right away next time you notice yourself not keeping up with the chlorine demand.

I've SLAM-ed a couple of times since owning the spa and it seems to help until my wife and I go back into the spa. Then its right back to the same issue of FC dropping quickly. Totally makes sense about the CYA though. My main desire for keeping the CYA low is to lower the required FC so that our swim suits don't reek of chlorine, and my wife doesn't complain about the smell. That's the whole reason I went with the dichlor + bleach method. My wife hates the smell of chlorine and hasn't complained yet since I have made the switch. The only issue now is the dry skin...

 

[bredwrd]

You're absolutely right to keep the CYA levels low.

If SLAM-ing isn't effective, then I'd suggest purge, drain and re-fill.

 

[proavia]

When was the last time you fully drained the spa?
When was the last time you did an Ahhsome purge?

 

[JoyfulNoise]

Try adding magnesium CHLORIDE (note - NOT epsom salt) to your hot tub and see if that helps with dryness. Epsom salt is mag sulfate but sulfates are bad for your heater. Chloride is fine because you already have plenty of it in the water anyway.

You might also try running the tub with a Saltron mini SWG.

 

[Mdragger88]

Are u testing after adding chlorine to see where it actually got u? If it really increased by 21ppm? as that’s what PoolMath says 6oz of 10% should yield.
Maybe your bleach is old? Or perhaps you have a demand issue & a purge & refill is in order.
I have a 200 gal. Tub. & the most I ever add after a soak (whether it’s dichlor or bleach) is Enough to get to around 10-12ppm - my cya is 20-30.
Also you can add salt for the feel if u want.
As well as reducing ch if possible depending upon your fill water.

 

[Wineguy5942]

When was the last time you fully drained the spa?
When was the last time you did an Ahhsome purge?

Spa was drained and filled the end of February when I began doing the dichlor and bleach method. The Spa is also new, and was set up mid January, so I doubt it needs a purge already.

 

[JoyfulNoise]

Spa was drained and filled the end of February when I began doing the dichlor and bleach method. The Spa is also new, and was set up mid January, so I doubt it needs a purge already.

Nope. New spas actually NEED to be purged right away. They are pressure tested at the factory and filled with water to ensure operation and no leaks. Then they are drained. Stagnant water is left in the plumbing and biofilms and bacteria grow. You will be surprised by all the crud that comes out of a “new” hot tub.

 

[Wineguy5942]

Try adding magnesium CHLORIDE (note - NOT epsom salt) to your hot tub and see if that helps with dryness. Epsom salt is mag sulfate but sulfates are bad for your heater. Chloride is fine because you already have plenty of it in the water anyway.

You might also try running the tub with a Saltron mini SWG.

Thanks for the advice on the magnesium. I might give it a go and see what happens. I already use borate because I was under the assumption that it helped with the feel of the water as well as maintaining pH.

Are u testing after adding chlorine to see where it actually got u? If it really increased by 21ppm? as that’s what PoolMath says 6oz of 10% should yield.
Maybe your bleach is old? Or perhaps you have a demand issue & a purge & refill is in order.
I have a 200 gal. Tub. & the most I ever add after a soak (whether it’s dichlor or bleach) is Enough to get to around 10-12ppm - my cya is 20-30.
Also you can add salt for the feel if u want.
As well as reducing ch if possible depending upon your fill water.

It seems to get up to around 16ppm so maybe the bleach IS old?? I'm used to bleach having a very strong "bleachy smell" to it and I can't even smell this stuff until it has been added to the water. I have a water softener that I use to partially fill the spa so I have the ability of lowering the Calcium. I was afraid of getting it too low to where it would affect my CSI??

 

[Wineguy5942]

Nope. New spas actually NEED to be purged right away. They are pressure tested at the factory and filled with water to ensure operation and no leaks. Then they are drained. Stagnant water is left in the plumbing and biofilms and bacteria grow. You will be surprised by all the crud that comes out of a “new” hot tub.

I have ahhh some, do I need to use new water to do a purge or can I just add it to my current spa water and then drain and replace?

 

[Newdude]

Add to existing water once you've committed to draining. It may take several rounds and the subsequent rounds use a half dose each Scoop out the foam with a pool net before it dries on the sides of the tub for easier cleaning. Wipe the waterline with paper towels 3 times mid purge and it will save alot of elbow grease afterwards.

If you don't get much the 1st time, do another. If that gets more curd than the first, keep going until you get a clean round.

Once done and drained, I filled but only up to the suction ports and cycled the jets quickly to empty the pipes, drained again and filled new.

 

[JoyfulNoise]

Wet/dry shopvacs are good for sucking up all the foam and crud that comes out. You can also suction out the ports as it is draining. The Ahhsome website has some great instructional videos with lots of good tips.

 

[wireform]

Make sure you don't forget to clean the filter.

 

[5tan]

My skin dries out at 5ppm FC too, so I would bet that's 95% of the problem. I like 2ppm FC for a 1-person soak, 3ppm for 2 people, and 5ppm if there's 3 or more. Instead of being the first to jump into 5ppm FC water, wait until a few other people have soaked in it with jets on for 10-20 minutes, then jump in when the FC is closer to 3.

Definitely do an Ahhsome purge if you haven't already, even on a brand new tub. My FC dropped quickly until I did this. The QuickVac and QuickDrain tools are great for this. Don't forget to hyperchlorinate your water while doing the purge, and to open up the drain so that long one-way tube gets cleaned out too.

If you have an ozonator, that will also make your FC and CC drop quickly. Immediately after a soak, I add chlorine and run my ozonator for 4-8 hours, which consumes most if not all of the FC, then I disable the ozonator and top up with more chlorine to maintain a baseline FC level.

Frequently (depending on your usage, weekly or biweekly), take out your filters and use pressurized water to rinse dead skin and other detritous from your filter, especially when you notice high chlorine demand. Every 2-4 weeks you should soak the filters for 6-24 hours in a chemical filter cleaner (most cleaners' primary ingredients are sodium carbonate and sodium percarbonate). A dirty filter will burn up FC.

I too require a lot of 10% pool chlorine after each soak, each soak usually comprises 2-4 people for several hours, so that's pretty heavy use, plus its a big tub. Keep adding until you test 5-10ppm FC. I usually add between 200-400mL after each heavy session. Who knows if it's actually 10%, as it degrades after manufacturing, in transit, in storage, etc. I buy only one jug at a time and store it in cold places to minimize this degradation, and try to pick the most recent lot code when buying.

My water metrics:
CYA: 20
FC 3-5ppm (superchlorination to 10ppm after each heavy soak)
pH 7.2, will allow it to rise from normal use aeration to 7.6 before knocking it back to 7.2. pH of normal skin is mildly acidic, 4.5–6.0, pH of tears is 6.5-7.6, see Role of pH Value in Clinically Relevant Diagnosis and Environmental Conditions and Tear Chemistry - Considerations in Contact Lens Use Under Adverse Conditions - NCBI Bookshelf and Normal Human Tear pH by Direct Measurement, so it's more comfortable on skin to keep the pH closer to 7.2. Added benefit is that chlorine's sanitizing power is stronger at lower pH, so you need less chlorine to achieve the same kill rates and kill times.
TA: 100, even though my fill water is 30 and I don't add any TA increaser (baking soda). It's probably from the pool calcium chunks I use.
CH: 180 for the purpose of anti-foam, raised from 30 so quite a bit of pool calcium increaser is needed after a fresh fill.
BOR: 50ppm, works beautifully at buffering pH

I use one Nature2 mineral stick and one knockoff Nature2, both at the same time. No idea if they do anything useful, but doesn't seem to hurt.

 

[DT835]

Second the comments about adding salt to your water. It certainly did help the feel of the water in my Hot Tub.

The one parameter that you did not list is the temperature of the water. A higher temperature will dry your skin much faster. It could be that your wife will have to get into the habit of moisturing her skin after using the Hot Tub or Shower.

 

[PineyVermont]

Second the comments about adding salt to your water. It certainly did help the feel of the water in my Hot Tub.

The one parameter that you did not list is the temperature of the water. A higher temperature will dry your skin much faster. It could be that your wife will have to get into the habit of moisturing her skin after using the Hot Tub or Shower.

When you say add salt to the water for the feel, do you mean you can do that even if you don't have a salt water "system"? And if so, any particular type/amount? Have a spouse with some psoriasis issues, ocean swimming does wonders.

 

[wireform]

Salt can be added to the pool even if its not set up for SWCG and just for beneficial reasons. As it's been mentioned every once in a while for feel.....

 

[Mdragger88]

When you say add salt to the water for the feel, do you mean you can do that even if you don't have a salt water "system"? And if so, any particular type/amount? Have a spouse with some psoriasis issues, ocean swimming does wonders.

Salt - Further Reading

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