Calcium Hardness is another imporarnt test that you need to keep your water balanced(the other two being pH & total alkalinity). So when you are testing for calcium hardness you will be measuring how much soft or hard water you swimming pool has at any given moment. So if the water hardness level is too high or low then it will contribute to unbalanced water.
So why is Testing for Calcium Hardness important?
You need to test for calcuim hardness beacuse it will allow you to maintain balanced pool water and also testing for calcuim hardness can prevent any damage from happing.
Water with low levels of calcium hardness could appear as sparkling clear water, but in fact the water could be corroding surfaces of the pool. So this is one big reason why you should test for calcium hardness as it could cost more to repair your pool than to buy a test kit.
The good thing about calcium hardness is that it does not change rapidly over a short amount of time, so you would only need to test for calcium hardness occasionaly. A monthly test is recomended or any time you make a big change to the pool e.g draining the pool and added fresh water back into the pool.
if the calcuim hardness in the pool is below 70 mg/l as CaCO3 the water is likey to be corrosive tothe pool structure and have a "calcuim demand". Ideally the level should be raised to at least 200mg/l by the addtion of calcium chloride flake- 1.5 kg added to each 50 m3(11.000 gall) of pool water will raise the calcium hardness by 20 mg/l
Test Methods to Test for Calcuim Hardness on Swimming pools
There are many different methods that you can use to test for calcium hardness. One way is buy using Test Kits. You can find inexpensive water hardness test kits, or you can get a pool test kit which had proivde test for a wide range of water testing inlcuding calcuim hardness. Here are some examples of water testing kits you can buy with different ranges like
Palintest Contour Comparator Balanced Water Kit
Palintest Contour Comparator Balanced Water Kit (with Cyanuric Acid)
Lovibond Checkit 5 in 1 Comparator Kit
Lovibond MD110 Pool Control 6 in 1 (New with bluetooth)
Palintest Pool Test 6 Photometer Range
Palintest Pool Test 10 Photometer
These all will test for different ranges of calcium hardness. Using test kits is the most accruate way of measuring calcium hardness, easpically if its a water hardness test kit.
You can also get Calcium Hardnes tablets, which you can get in either foil blister pack or count bottles. 50, 100 and 250 box sizes are available.