First Hot Tub and I'm very, very confused!
- Thread starter karlahurley
- Start date
So I've got these readings today:
PH - 7.8
FC - 6.5
CC - .4
TA - 50
CYA - 0 (though I added some dichlor yesterday)
A couple of questions:
Should I have CYA in the spa to soak?
Why did adding dichlor yesterday not get rid of the CC?
I just added what Pool Math told me to add of MA to get PH to 7.0. Should I add anything else?
I also just received some Gentle Spa in the mail, when should I add that?
Thanks
PH - 7.8
FC - 6.5
CC - .4
TA - 50
CYA - 0 (though I added some dichlor yesterday)
A couple of questions:
Should I have CYA in the spa to soak?
Why did adding dichlor yesterday not get rid of the CC?
I just added what Pool Math told me to add of MA to get PH to 7.0. Should I add anything else?
I also just received some Gentle Spa in the mail, when should I add that?
Thanks
- May 23, 2015
- 24,641
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You have CYA in the tub, it’s just not at a measurable level yet (you’re still under 30ppm). How much dichlor have you added by weight?
You want some CYA in the tub as chlorine will be very harsh on your skin without it. But it only takes about 10-15ppm to reduce (buffer) the active chlorine to tolerable levels. I’d give it a 15min soak and see how it feels. If you’re still comfortable, then it’s ok to use it.
CCs are a persistent problem in hot tubs. Inorganic CCs (monochloramine, dichloramine and nitrogen trichloride) are easily oxidized and readily outgassed. Organic CCs (those where chlorine reacts with urea, creatinine, arginine, etc) do not oxidize easily or outgas much. So once a tub starts to build up a persistent level of CCs, you have to drain and refill. A secondary, non-halogen oxidizer like a UV sterilizer, helps to oxidize organic contaminants and reduce persistent CCs BUT few tubs have that. Indoor pools tend to have similar problems because they do not get exposed to sunlight.
Potassium monopersulfate (MPS) is a non-chlorine oxidizing shock that can help with CCs BUT it interferes with the standard CC test and adds sulfates to your water which is bad for heaters and plaster surfaces.
If your CCs are less than 1.5ppm, then most people can tolerate a tub with a small CC load.
Also, you want to stop dropping your pH and TA now as your TA is getting on the low side. You don’t want your TA to go to zero and then have your pH crash. The dichlor you are adding is acidic enough to help keep the pH down.
You want some CYA in the tub as chlorine will be very harsh on your skin without it. But it only takes about 10-15ppm to reduce (buffer) the active chlorine to tolerable levels. I’d give it a 15min soak and see how it feels. If you’re still comfortable, then it’s ok to use it.
CCs are a persistent problem in hot tubs. Inorganic CCs (monochloramine, dichloramine and nitrogen trichloride) are easily oxidized and readily outgassed. Organic CCs (those where chlorine reacts with urea, creatinine, arginine, etc) do not oxidize easily or outgas much. So once a tub starts to build up a persistent level of CCs, you have to drain and refill. A secondary, non-halogen oxidizer like a UV sterilizer, helps to oxidize organic contaminants and reduce persistent CCs BUT few tubs have that. Indoor pools tend to have similar problems because they do not get exposed to sunlight.
Potassium monopersulfate (MPS) is a non-chlorine oxidizing shock that can help with CCs BUT it interferes with the standard CC test and adds sulfates to your water which is bad for heaters and plaster surfaces.
If your CCs are less than 1.5ppm, then most people can tolerate a tub with a small CC load.
Also, you want to stop dropping your pH and TA now as your TA is getting on the low side. You don’t want your TA to go to zero and then have your pH crash. The dichlor you are adding is acidic enough to help keep the pH down.
You know, I must have gotten a little confused late in the evening last night. I have spent each evening studying and trying to get a handle on all that I need to learn. My notes say that I added 1.2 tsp dichlor.
After adding a little bit more of the MA as stated above, my TA is holding at 50 and the PH is at 7.6.
I added 12 oz of Gentle Spa earlier (boric acid?).
And I do have some CYA I could add to help ease the harshness, should I do that?
Is the CC something that I can get from tap water that was not run through a prefilter? Did I understand you correctly, that shocking with FC can lower CC?
I can't begin to express how grateful I am for your help, thank you very much.
After adding a little bit more of the MA as stated above, my TA is holding at 50 and the PH is at 7.6.
I added 12 oz of Gentle Spa earlier (boric acid?).
And I do have some CYA I could add to help ease the harshness, should I do that?
Is the CC something that I can get from tap water that was not run through a prefilter? Did I understand you correctly, that shocking with FC can lower CC?
I can't begin to express how grateful I am for your help, thank you very much.
- May 23, 2015
- 24,641
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
OK, based on your added amount of dichlor your CYA should be around 10ppm. That's probably enough to reduce the harshness a bit. So I would let the FC come down to about 2ppm and give the tub a try and see how it feels...contrary to what the pool "professionals" say, your skin isn't going to melt off your bones...Keep using the dichlor to maintain the proper FC levels and keep checking the CYA every few teaspoons or so. Like I said, for ebery 10ppm FC added by using dichlor, your CYA should go up by 9ppm. At some point you'll hit 30ppm CYA (the lowest measurable concentration using the turbidity test) and then you should switch over to bleach exclusively.
The Gentle Spa stuff is a proprietary mixture of sodium tetraborate pentahydrate and boric acid. It's designed to add borates to your water in a pH neutral way. It's probably the most expensive way to add borates but, since you have it, you might as well use it. The amount you added should have raised your borate level to 40ppm. You might want to get some LaMotte borate test strips just to verify that you have a measurable amount of borates in the spa. The strips are cheap and will give you the ballpark value.
Yes, shocking does break down some of the CCs. The inorganic CCs will be decreased by shocking. The organic CCs tend to not get further oxidized by chlorine and those are the persistent ones. They simply build up over time and there's no easy way to get rid of them.
If your municipal water supplier uses chloramination as a disinfection process (most do), then tap water can have a very measurable CC level. However, it would the inorganic CCs and so those would go away with shocking. You could pre-filter the tub water on every fill but my understanding is that those pre-filters are expensive and they don't treat enough of the water to make it economical.
Thank you very much
My best friend is visiting Arizona right now. He loves it, I'm worried he might stay!
My best friend is visiting Arizona right now. He loves it, I'm worried he might stay!
- May 23, 2015
- 24,641
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Winters are the best here. 60’s during the day, chilly at night. I can still BBQ anytime I want. Lots of outdoor fun.
Oh, and no snow to shovel!!!
Having grown up and lived in NY for most of my life, I’m way past all that snow stuff....it stays up in the mountains around Tucson and I can visit it whenever I want.
Oh, and no snow to shovel!!!
Having grown up and lived in NY for most of my life, I’m way past all that snow stuff....it stays up in the mountains around Tucson and I can visit it whenever I want.