Balance Hot Tub Water

[chrispitt]

What do you need to balance hot tub water?

[DigitalMan]

What do you need to balance hot tub water?

Being new to Hot Tubs I also have this question, however more so, what are balanced readings? I've searched a bit but have not got a clear indication of what "BALANCED" water is. Thanks!!

[chem geek]

Balance means proper values for the most relevant water quality parameters:

• pH between 7.2 and 7.8, usually between 7.5 and 7.8 when using hypochlorite sources of chlorine.
• Total Alkalinity (TA) of 50 ppm or so when using hypochlorite sources of chlorine or 80 ppm or so when using acidic sources (bromine tabs; Dichlor), though really the TA should be set a level that makes the pH tend to not rise or fall over time.
• Calcium Hardness (CH) at 120-150 ppm to prevent foaming though it can be lower if foaming is not an issue.
• Cyanuric Acid (CYA) at 30-40 ppm if using chlorine with the Dichlor-then-bleach method (for Dichlor-only, the CYA will rise over time)
• 50 ppm Borates if using the Dichlor-then-bleach method or when additional pH buffering against a rise in pH is desired

Also, there should be a disinfectant level, Free Chlorine (FC) or Total Bromine (TB) or MPS (for the Nature2 system), in the water at all times (especially in the long time between soaks).

If one has a plaster hot tub or exposed grout in tile, then balance also refers to the Calcite Saturation Index (CSI) which is calculated from the above water parameters. You can use The Pool Calculator to calculate it. However, most hot tubs are acrylic with no plaster or grout so that the CSI is not relevant except that you don't want it too high (> 0) as you can get calcium carbonate scaling, especially in the gas heat exchanger.

[DigitalMan]

Thank you! This help a lot.

[waterbear]

Balance means proper values for the most relevant water quality parameters:

• pH between 7.2 and 7.8, usually between 7.5 and 7.8 when using hypochlorite sources of chlorine.
• For bromine this is 7..2 to 8.0

​

• Total Alkalinity (TA) of 50 ppm or so when using hypochlorite sources of chlorine or 80 ppm or so when using acidic sources (bromine tabs; Dichlor), though really the TA should be set a level that makes the pH tend to not rise or fall over time.
• With hot tubs this is usually much lower than in a swimming pool because of the constant aeration that causes pH rise.

• Calcium Hardness (CH) at 120-150 ppm to prevent foaming though it can be lower if foaming is not an issue.

• Cyanuric Acid (CYA) at 30-40 ppm if using chlorine with the Dichlor-then-bleach method (for Dichlor-only, the CYA will rise over time)
• Not needed for Bromine.

​

• 50 ppm Borates if using the Dichlor-then-bleach method or when additional pH buffering against a rise in pH is desired
• Useful in any tub, no matter what the sanitizer, IMHO.

Also, there should be a disinfectant level, Free Chlorine (FC) or Total Bromine (TB) or MPS (for the Nature2 system), in the water at all times (especially in the long time between soaks).

THIS IS VERY IMPORTANT and is where most problem occur!