Cold Plunge Spa (ChillyGOAT)

[808patrick]

I am finding keeping my cold plunge, a MasterSpas Chilly GOAT balanced harder than I expected. The unit is about 170 gallons, includes a heat pump and UV sterilization, a K-1000 test kit, and precious little in included control.

My specific challenges are [I live in Hawaii so getting many things can be a hard,] how many hours a day should I run the pump/UV, how do I know if the UV is actually working, and even adding just tiny amounts of Sodium Dichlor makes my [combined]chlorine level spike making me use relatively substantial amounts of Potassium Peroxymonosulfate to get it down to recommended levels.

Currently we run the pumps about 6-7 hours a day and use it 70-80 minutes a day, with the setpoint at 55F. I do occassionally add ice to drop the temperature for myself to below what my wife wants.

Any suggestions on what I might be doing wrong or how to do it better? Running the pump/UV 24x7 is a challenge (8-9kWh/day).

 

[Bperry]

I am finding keeping my cold plunge, a MasterSpas Chilly GOAT balanced harder than I expected. The unit is about 170 gallons, includes a heat pump and UV sterilization, a K-1000 test kit, and precious little in included control.

My specific challenges are [I live in Hawaii so getting many things can be a hard,] how many hours a day should I run the pump/UV, how do I know if the UV is actually working, and even adding just tiny amounts of Sodium Dichlor makes my [combined]chlorine level spike making me use relatively substantial amounts of Potassium Peroxymonosulfate to get it down to recommended levels.

Currently we run the pumps about 6-7 hours a day and use it 70-80 minutes a day, with the setpoint at 55F. I do occassionally add ice to drop the temperature for myself to below what my wife wants.

Any suggestions on what I might be doing wrong or how to do it better? Running the pump/UV 24x7 is a challenge (8-9kWh/day).

UV destroys chlorine. If this is an outdoor spa, the sun provides plenty of UV but if it’s indoor that may just be what you have to use. Consumer grade units aren’t very powerful anyway.

Adding dichlor should not increase the CC level unless there is a contaminant in the water. But if your using MPS, that interferes with the CC test so you may have been chasing something that doesn’t exist.

You may want to consider a more comprehensive test kit. TFP recommends always following the CYA/FC chart to make sure the water is sanitized. It sounds like yours may have something in it for under chlorination.

 

[Mdragger88]

The k1000 only tests total chlorine up to 5ppm.
Fc (free chlorine/good stuff)
+
cc (combined chlorine/bad stuff)
= Total chlorine
You need to know how much of each you have separately to know what is going on.
And to be able to follow the
FC/CYA Levels.
The tf100 or Taylor k2006c contain all the tests you need including the fas/dpd test to check fc & cc separately & above 5ppm.

For Every 1ppm of fc you add with dichlor you also add approx. 1ppm of cya
The fc gets used up but the cya remains in the water until you replace water. For this reason we recommend only using dichlor until cya reaches 30ppm then switching to liquid chlorine.
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How do I use Chlorine in my Spa or Hot Tub?

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...

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Use PoolMath for calculating additions - i use google conversions to determine teaspoons etc.

 

[phonedave]

How often do you use your cold plunge?

My limited experience (I know two people that have them) is that they use them once per day, for like 5-10 minutes. If that is the schedule, I would just bring it up to SLAM levels after each use, and then let the UV bring it down over the next 24 hours. 170 gals requires some small dosing, and is going to move all over the place. That is why I would just run it up to SLAM, and let it drift down.