Suggested target FC with pool spa combo and Spillover?

[thegizzard]

I have been using the FC/CYA chart for setting my target FC. But I suspect my FC is low when using my spa. This is because my son has some hot tub rash. I read somewhere on this forum that spa has a higher bather load than the pool and that makes sense due to the temperature. So I am looking for some suggestions on what my target FC should be since I have a pool spa combo. I can set a different level on my chlorine generator for pool versus spa and previously the spa was lower than the pool. Now I think I should maybe set the spa higher than the pool. By the way I run my spill over for one hour in the morning and four hours in the evening.

My logs: PoolMath Logs

 

[Jimrahbe]

giz,

Have you actually tested the FC in the Spa?

How long does your son stay in the spa at one time?

It would be interesting to see what the FC and CC of the spa is just before use, and just after use.

Thanks,

Jim R.

 

[thegizzard]

giz,

Have you actually tested the FC in the Spa?

How long does your son stay in the spa at one time?

Yesterday morning I tested the spa Fc and it was 4, I thought it was low. But this morning I tested the pool and it was 3.5 (low). I suspect the spa and pool are the same because of the spillover — when I am not using the spa.

That said, I will take measurements of the pool and spa before and after I use the spa next time and report back.

 

[mknauss]

You should be able to adjust the % generation of your SWCG when in Spa mode via your automation. Raise it some to be sure the spa is staying chlorinated while in Spa mode.

 

[thegizzard]

Agreed. The interesting thing is, the PB set the spa chlorination % lower at startup. He said because the spa is smaller. Now it seems it should be higher.

 

[Jimrahbe]

Giz,

Well, in theory, it should be lower as you are using the same cell to chlorinate a large pool vs. a very small spa.

My automation defaults to about 10% of the pool setting.. You can however, manually set it.

Just because your son has a spa rash, does not necessarily mean the FC is to low.

Thanks,

Jim R.

 

[thegizzard]

Giz,

Well, in theory, it should be lower as you are using the same cell to chlorinate a large pool vs. a very small spa.

My automation defaults to about 10% of the pool setting.. You can however, manually set it.

Just because your son has a spa rash, does not necessarily mean the FC is to low.

Thanks,

Jim R.

Thanks. The rash is what I am really trying to deal with. Any suggestions?

 

[Jimrahbe]

Giz,

I don't, but it would be nice to know the FC and CC of the spa, before and after bathing, and how long your son stays in the spa.

Let's see if Matt, has any input about spa rash. Calling @JoyfulNoise

Thanks,

Jim R.

 

[JoyfulNoise]

The rash could be from anything. I sincerely doubt you have pseudomonas growing if the spa is being regularly transferred into the pool through overflow. It’s more than likely that your son is spending too much time in front of the jets at too high a speed causing mechanical irritation of the skin and/or spending too much time in the spa in general. As well, if he’s using any kind of sunscreen products, those can cause irritation with chlorinated pool water. The cheap aerosol ones are especially bad because the propellants and chemical diluents used can be irritating to sensitive skin. It’s best to use high quality products like Nutragena or Ceravé that are applied by hand.

 

[thegizzard]

Thanks guys. We are going to switch up the sunscreen and do some measurements over the weekend. I’ll report back.

 

[thegizzard]

Just a brief update. I recently switched from pH 7.8 target to pH 7.6 target. My Acid pump runs from 3am - 4am and by the time we wake up pH is 7.6 and by the late evening it is 7.8.

I have noticed an improved feel to the water. Before the change, the water felt very dry, like it was a absorbing oils from my skin. It does not feel that way now. The water feels more natural.

The is the background to the changes in Chlorine levels I have discussing in this thread. This week we have a heat wave in Charlotte, NC and my FC demand is up. We are also using the pool more so our bather load is also up. In the past week I have adjusted the SWCG from 25% to 50% and I am monitoring twice a day to find the sweet spot with these changing conditions.

All of this to say, everyone including my Son is enjoying the pool more and there are no new rashes. I am not sure what is responsible for improvement, the lower pH or the higher Chlorine.

Either way I will keep monitoring and report back.

Note: yesterday I took some spa measurements before and after using the spa. I have included those in my logs below.

My logs: PoolMath Logs