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

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.

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.

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

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.

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 said:

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.

Click to expand...

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.

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.

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

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.

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.

DT835 said:

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.

Click to expand...

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 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.....

PineyVermont said:

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.

Click to expand...