Swim spa: pool or spa?

[Purrkitten]

I am a newbie (have had the swim spa for 3 months) and just getting set up in TFP. I have a swim spa that stays covered when not in use. I use it ~4 times/week, 1-2 hours per use. Since I exercise in it, sweat and saliva are probably a consideration (TMI?). The temperature is usually around 80-82 degrees, not typical spa temperature. BTW, I just ordered a TF 100 test kit. Up until now, I've been naively using test strips.

My question is on PoolMath, should I establish goals using pool or spa criteria?

 

[Agent99]

It sounds like a pool to me so I'd treat it as such. Welcome to TFP!

 

[Purrkitten]

Thanks, Chris. Appreciate the input.

 

[Isaac-1]

I would tend to treat it like a pool, but one that does not get much UV exposure and may need a source of supplemental oxidation either chemical like MPS or an Ozonator.

 

[Purrkitten]

I would tend to treat it like a pool, but one that does not get much UV exposure and may need a source of supplemental oxidation either chemical like MPS or an Ozonator.

Supposedly the swim spa comes standard with an ozonator. But I have no idea where it is, or how to tell if it is operating properly. I do use MPS once a week per the manufacturer's suggestion. Does UV exposure contribute to killing bacteria, etc?

Thanks for the response!

 

[chem geek]

No, the UV in sunlight is not the right wavelength for killing bacteria. It does break down chlorine and when that happens it produces powerful though short-lived oxidizers called hydroxyl radicals. So an outdoor pool exposed to sunlight tends to stay clear more easily from sunlight helping to break down bather waste and other organics in the water.

The disinfection that kills bacteria comes from chlorine.

 

[JVTrain]

With your volume I'd treat it like a pool. Despite being in CA, you could keep the CYA relatively low for your region because it will be covered most of the time. I'd start with 30 ppm CYA and maintain the required FC for that CYA from the CYA/Chlorine chart in my signature. It's probably most important to check your FC about 15-30 minutes after a swim and bring it up to your target FC at that time. You may need to maintain a lower TA (as low as 40-50 ppm) to keep the pH from rising too quickly because your swimming and the spa itself will generate a good amount of aeration. More aeration = faster carbon dioxide outgassing = faster pH rise. Lower TA helps combat this, but you need some TA to buffer the pH. I would recommend not using the mineral filter if possible as it likely contains silver and/or copper and could lead to green hair eventually if you've got blonde flowing surfer locks.

 

[Isaac-1]

Also be aware that MPS shows up as CC on the standard test kits, you need a special MPS elimination test to get true CC levels if you are going to routinely use MPS.

 

[Purrkitten]

With your volume I'd treat it like a pool. Despite being in CA, you could keep the CYA relatively low for your region because it will be covered most of the time. I'd start with 30 ppm CYA and maintain the required FC for that CYA from the CYA/Chlorine chart in my signature. It's probably most important to check your FC about 15-30 minutes after a swim and bring it up to your target FC at that time. You may need to maintain a lower TA (as low as 40-50 ppm) to keep the pH from rising too quickly because your swimming and the spa itself will generate a good amount of aeration. More aeration = faster carbon dioxide outgassing = faster pH rise. Lower TA helps combat this, but you need some TA to buffer the pH. I would recommend not using the mineral filter if possible as it likely contains silver and/or copper and could lead to green hair eventually if you've got blonde flowing surfer locks.

Thanks for the feedback! I'm going to have to wait for my new test kit before I can attempt to get FC, CYA, TA, and pH in the proper ranges. All I've got right now is test strips. As for the CYA, I know it was too high (133 ppm according to the local pool store test) and the water was cloudy. I drained about 3/4 of the water yesterday, and refilled. So I don't know the exact CYA level right now. It was the TFP website that told me that I had the problem because I had been using dichlor granules. I'll post my results when the kit arrives, but I will definitely go back to your advice to determine the next steps.

As for the mineral filter: no blonde locks here. Mine are more gray than blonde! So I guess the mineral filter isn't gonna hurt anything!

 

[Purrkitten]

Also be aware that MPS shows up as CC on the standard test kits, you need a special MPS elimination test to get true CC levels if you are going to routinely use MPS.

I ordered the TF-100 test kit today - does it include the MPS elimination test? I don't see the MPS elimination test as an individual test that can be purchased separately.

Thanks for the feedback!

 

[chem geek]

No it doesn't. That's the Taylor K-2042 kit. You might try seeing if you can get by without using the MPS. If the ozonator you think you have is working, it should help to control CC.