Test Results: Do I Need To Drain & Refill?

[ugadawgs311]

I have a Hotspring hot tub with a Freshwater Salt System. I've always tested the water using regular test strips. The results always came back pretty normal, and the water has been clear and clean for months now (although I have had to make minor, normal adjustments to the chemicals over time). I recently purchased a new Taylor K2006 Test Kit for my pool and decided to test the hot tub water too. The results were a little disconcerting:

• FC: 5
• CC: 0.5
• pH: 7.0
• TA: 190
• CH: 560

I think things are ok except for the obviously high TA and CH levels. My tap water is low in calcium, so that high CH must be due to to CH increaser I put in a few times. At this point, should I just drain and refill the tub? I have a Vanishing Act package that's supposed to lower CH levels, but I wonder if my CH is just so high (along with TA) that it makes sense to drain the water. Any thoughts?

 

[PoolStored]

At this point, should I just drain and refill the tub?

Why not just exchange water with the pool?

 

[ugadawgs311]

Why not just exchange water with the pool?

What do you mean? Drain the hot tub water to the pool? I’m currently in the middle of SLAM on the pool, and it’s looking very clean now, so I’d like to keep it that way and not mess up any other chemicals.

Even if I drained the hot tub to to the pool, you’re still suggesting that I fill the hot tub with new, fresh water, right?

 

[PoolStored]

What do you mean? Drain the hot tub water to the pool? I’m currently in the middle of SLAM on the pool, and it’s looking very clean now, so I’d like to keep it that way and not mess up any other chemicals.

Even if I drained the hot tub to to the pool, you’re still suggesting that I fill the hot tub with new, fresh water, right?

Is the CH of your pool 650? Exchanging water will bring down your CH in the spa, and have a small dent in your pool CH. Or any other parameter for that matter. How big is your spa?

 

[ugadawgs311]

Is the CH of your pool 650? Exchanging water will bring down your CH in the spa, and have a small dent in your pool CH. Or any other parameter for that matter. How big is your spa?

CH in the pool was 90 as of 7 days ago.

The hot tub is 360 gallons.

 

[PoolStored]

CH in the pool was 90 as of 7 days ago.

The hot tub is 360 gallons.

360 gallons vs. 22,500? I'd swap that in a second. Will solve your CH problem, and even the elevated FC will kill anything coming from the spa or in the spa...

 

[ugadawgs311]

360 gallons vs. 22,500? I'd swap that in a second. Will solve your CH problem, and even the elevated FC will kill anything coming from the spa or in the spa...

Would the high FC level of my pool (16) affect the SWG in the hot tub?

Also, any tips for swapping the water? Other than a 5 gallon bucket

 

[Oly]

Guessing this is a stand alone spa?
When was the last time you changed the water?
Have you ever purged the plumbing since new with a strong surfactant?

 

[ugadawgs311]

Guessing this is a stand alone spa?
When was the last time you changed the water?
Have you ever purged the plumbing since new with a strong surfactant?

Yes it’s a stand alone spa.
Last purge was early 2022 (that went by quick!) when I purged it with Ahh-Some.

 

[Oly]

I would suggest you purge it with Ahh-Some while raising the FC, clean the filters, drain and refill with fresh water.
Follow this sanitation plan for the refill... How do I use Chlorine in my Spa (or pool)?
Then use your new test kit to monitor your water chemistry going forward and avoid getting your CH so high.

 

[ugadawgs311]

I would suggest you purge it with Ahh-Some while raising the FC, clean the filters, drain and refill with fresh water.
Follow this sanitation plan for the refill... How do I use Chlorine in my Spa (or pool)?
Then use your new test kit to monitor your water chemistry going forward and avoid getting your CH so high.

Thanks! I figured it’s probably time for new water, especially with the high CH and TA.

Will CH this high (560) cause tremendous harm to my tub? In other words, should I avoid using the tub until I can drain and refill it?

 

[Oly]

High CH could lead to scale formation if the CSI is high which it will be if your pH gets above 7.5. You must be adding acid regularly with TA of 190ppm, hard to imagine your pH staying at 7.0 for very long. Did you test your CYA ppm? Are you having any issues with Calcium scale in your salt cell? I assume the Freshwater Salt System is a SWCG? What is the Vanishing Act package? Lowering CH levels requires water replacement directly or with reverse osmosis. What is your typical weekly tub usage per week in number of people hours?