Sequestering Agent: Once or Weekly?

[Terv]

Excerpt from "How do I use Bromine in my spa?"

Here is a step by step:
1) On each fill balance the water (adjust TA and pH. Add calcium if below 125 for acrylic spas or below 200 for plaster.) If you have metals in your water add a metal sequesterant.

Calcium: Is the target 125 ppm?
(APSP range is 100 - 800 ppm. Ideal 150 - 250 ppm.)

Sequesterant: Our hot tub manufacturer recommends adding a sequestering agent once a week as a stain and scale controller. I am wondering if that is a blanket statement for warranty purposes because they do not know where their hot tubs will end up. My water out of the tap: Copper 0 ppm, Iron 0.1 ppm, TDS 200 ppm. The last time I used the Manufacturer's sequestering agent there was an increase in foam and a de-foamer was recommended. I found several one time sequesterants online. Is there a recommended brand? Once or weekly? Do sequesterants prevent scale build up?

 

[pooldv]

I would not add sequestrant without a demonstrated need to do so. I am not aware of any benefit that a sequestrant provides against scaling. Controlling PH is be best prevention for scaling. In a hot tub it is best to actively lower TA to 50 then add 50 ppm borates.

There is an in depth discussion on PH, TA and borates here, How do I use Chlorine in my Spa (or pool)?

 

[Terv]

I would not add sequestrant without a demonstrated need to do so. I am not aware of any benefit that a sequestrant provides against scaling. Controlling PH is be best prevention for scaling. In a hot tub it is best to actively lower TA to 50 then add 50 ppm borates.

There is an in depth discussion on PH, TA and borates here, How do I use Chlorine in my Spa (or pool)?

Thank you for the reply. You just confirmed what I was thinking. Everytime I add something another problem emerges. Yes, I have read both discussions.

Calcium: What is the ideal calcium target? 125 ppm?

Again thank you.

 

[pooldv]

Agreed! That is the TFP mantra, only add what you need based on accurate testing. CH is really only needed in a hot tub (non-plaster) to control foaming if it is a problem. Up to 150 ppm is recommended. 125 is fine. I don't test mine, but would expect it to be in the 300s.

 

[RNDEBBIEROSE]

My hot tub dealer delivered mine when I wasn't home, and actually added a sequesterant to my first fill. I have city water and no metal issues. If I was here when they came, I wouldn't have allowed it. The second fill I did, I did NOT add it. No problems, as I suspected. You know if you need a sequesterant. Don't let them Cha-Ching you

 

[duraleigh]

Terv,

I cannot make the connection between sequestrants and the borate article you published. Help me understand.