I have a 434 gal Bullfrog A7L and bought the Saltron Mini SWG to use with it. I'm researching the levels I want to use, and I noticed the TFP Chlorine/CYA chart and PoolMath app show higher recommended levels of CYA and FC compared to the liquid chlorine table. For SWG, the app shows 70-80 ideal CYA and recommended FC of 4-11 if I choose CYA of 75. For liquid chlorine, the numbers drop closer to those I've seen recommended in posts here (CYA of 40-50, FC of 4-8 if I choose CYA of 45). Is there something about using a SWG that changes the ideal target levels? Thanks in advance!
Recommended levels with SWG
- Thread starter flyz
- Start date
- Jul 21, 2013
- 53,228
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Welcome to TFP.
The Chlorine/CYA chart is for outdoor uncovered pools. That is not what you have and I will assume your spa is covered when not in use.
You will see the notes on the bottom of the page say:
For indoor pools we recommend CYA between 20 and 30ppm. The reasoning for using CYA indoors is quite different. For more information please ask on the forum.
Your spa is like an indoor pool although a spa is not a small pool. CYA of around 20-30 ppm is all you need to buffer the harshness of chlorine.
www.troublefreepool.com
The Chlorine/CYA chart is for outdoor uncovered pools. That is not what you have and I will assume your spa is covered when not in use.
You will see the notes on the bottom of the page say:
For indoor pools we recommend CYA between 20 and 30ppm. The reasoning for using CYA indoors is quite different. For more information please ask on the forum.
Your spa is like an indoor pool although a spa is not a small pool. CYA of around 20-30 ppm is all you need to buffer the harshness of chlorine.
How do I use Chlorine in my Spa (or pool)?
If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...
www.troublefreepool.com
Thank you - that makes sense. What about the SWG - does that change my goal numbers at all? I read about the relationship for an outdoor pool changing since the SWG is generating chlorine slowly over time in gaseous form (and fighting the sunlight), but since the spa is indeed covered most of the time can I just use the normal non-SWG table entries?
- Jul 21, 2013
- 53,228
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Yes. That is where a spa is not a small pool.
A spa needs a higher chlorine level since it is kept at a higher temp and has a higher bather load for the water volume. Both of which consumer more chlorine.
Ok, thanks again! These are the steps I plan to follow - please correct me if you see glaring errors.
- Fill w/ 50% hard and 50% soft water to work toward a CH of about 150
- Add salt to reach 2500 (per Saltron Mini instructions)
- My TA and pH start high - Add muriatic acid in small doses with aeration in between to reach target TA of 50 and pH of 7.6
- Add CYA to reach 30
- Add bleach to reach FC of 4
- Turn on SWG and experiment with settings over the next few weeks to ensure FC stays about 4 (add bleach as necessary after we soak)
- Check FC and pH often until I get a feel for what it's going to take
- Fill w/ 50% hard and 50% soft water to work toward a CH of about 150
- Add salt to reach 2500 (per Saltron Mini instructions)
- My TA and pH start high - Add muriatic acid in small doses with aeration in between to reach target TA of 50 and pH of 7.6
- Add CYA to reach 30
- Add bleach to reach FC of 4
- Turn on SWG and experiment with settings over the next few weeks to ensure FC stays about 4 (add bleach as necessary after we soak)
- Check FC and pH often until I get a feel for what it's going to take
Last edited:
I followed fairly closely the steps above and these are my current numbers:
FC = 5
pH = 8.1
TA = 70
CH = 150
CYA = 60
Salt = 3000
The pH seems to be rising over the period of about 4 hours...it went from my target 7.5 up to 8.1. I just added 3 tsp of 20 Baume muriatic acid per PoolMath to bring it back down toward the target. If I keep repeating this procedure, should I eventually see it stabilize?
FC = 5
pH = 8.1
TA = 70
CH = 150
CYA = 60
Salt = 3000
The pH seems to be rising over the period of about 4 hours...it went from my target 7.5 up to 8.1. I just added 3 tsp of 20 Baume muriatic acid per PoolMath to bring it back down toward the target. If I keep repeating this procedure, should I eventually see it stabilize?
- Jul 21, 2013
- 53,228
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Maybe, maybe not. Does your spa have an ozone system?
Aeration from the ozone and from the spa circulation causes the pH to rise.
Oh, yes, it does have an ozone system. Is that going to make application of this method difficult? I suppose there might be a way to disable it - didn't even think of that.
- Jul 21, 2013
- 53,228
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60