Hot Tubs Engineered for the World’s Harshest Climates

Arctic Spas Manuals


105. Establishing Correct Water Chemistry

1.10.3 Establishing Correct Water Chemistry


The following steps provide guidance to help establish correct chemically balanced water. To help ensure chemicals dissolve appropriately it is good practice to first mix/dissolve the chemical in an uncontaminated container of hot water before carefully adding to the spa water.

Steps to Establish Chemically Balanced Water With Onzen


Step 1. Test and Adjust Calcium / Total Alkalinity

(a) Test Calcium hardness. Level should be between 50-150 ppm. If high, lower with a stain & scale controller such as Arctic Pure, Best Defence, to help hold the Calcium in suspension.

NOTE: Salt systems perform best with Low Calcium levels.

(b) Test Total Alkalinity. It should be 80 – 100 ppm (100 max). If high, lower Total Alkalinity with Arctic Pure, Adjust Down (pH Down) or muriatic acid. Do not raise Total Alkalinity!

WARNING: Skipping these steps on Start-up can cause scaling problems and cloudy water that may not be covered under warranty.

NOTE: Use all products according to directions on the bottle.


Step 2. Test and Adjust pH

Test pH. Levels should be between 7.2 – 7.6. If pH is high, (over 7.6) add Arctic Pure, Adjust Down. If pH is low, (under 7.2) add Arctic Pure, Adjust Up.

NOTE: Use all products according to directions on the bottle.

NOTE: Salt systems naturally drive pH levels to increase, strive to achieve a Balanced pH level.

NOTE: High pH will cause calcium to precipitate (fall out of suspension). The problem with calcium falling out of suspension is that it collects on the heater and pump, and shortens their life.


Step 3. Mix Salt Crystals

Dissolve 1/3 of the minimum recommended salt dosage in a 5 Gallon (20 litre) pail of hot water. Refer Arctic Spas – Onzen Salt Dosage Chart contained in this guide.