How do I decrease water hardness levels in my pool?

[alessiahayden66]

How do I decrease water hardness levels in my pool? Please suggest!

[zappalot]

To my knowledge you need to dilute the water. Increasing is possible by adding Calcium Chloride, but decreasing? Dilution....

 

What is the hardness level?

 

Of course this only works if your replacement water is soft. Else use a flocculant to clump together excess calcium and vacuum clean it out.

Edited February 8, 2018 by zappalot

[RichCor]

Some website commentaries suggest...

 

"While you can dilute, another option is modify the existing water chemistry via ion exchange

 

"An Ion exchange adds a tiny amount of salt (sodium) to your water to alter the binding qualities of the existing Calcium and/or Magnesium that are contributing to the water harness issue. Most use Sodium Chloride (the most common and most effective), very few if any use Potassium Chloride.

 

"Just be mindful, removing or binding too much Calcium from the water chemistry may cause calcium to be drawn from pool plaster or tile grout.

 

Also...

 

"The only way to reduce calcium hardness levels in pool water is through dilution with water of a lesser hardness. Over time, calcium hardness will naturally increase in pool water due to evaporation and possibly other factors unless the pool water is regularly diluted.

 

"While it may be difficult to reduce calcium hardness, it is possible to control it so that a potential problem such as cloudy water or scale formation is prevented. The best way to minimize the effect of high calcium levels is through the use of a sequestering agent. A sequestering agent is a compound that, when added to water, will chemically bond with calcium and other minerals to make them, in a sense, more soluble. This means that calcium will still be present, but in a form that is less likely to cloud water or form scale if the pH or other factors get out of balance. In addition, since calcium will still be in the water, you will not have the corrosion problems you would otherwise experience with soft water.

 

 "The ideal range for Calcium Hardness in swimming pools is 180 – 220 ppm, although others may use 200-400 as an acceptable range of hardness. For swimming pools located in hard water regions, where the tap water has Calcium Hardness levels of over 400 ppm, managing water chemistry takes a specific focus."

 

"The most important thing with hard water pools is to maintain low pH and low Alkalinity levels, especially as the water temperature increases. Hard water pools are less likely to become cloudy or produce scale when the pH level is kept around 7.2 and Alkalinity is below 100 ppm.

 

"The second most important thing with a hard water pool is to make regular use of a good Stain & Scale chemical, aka sequestrants or chelators. These chemicals bind up minerals and metals to keep them dissolved, to prevent staining and scaling, but they deplete rapidly.

 

"Thirdly, for pools with high calcium hardness levels, you may want to discontinue use of calcium hypochlorite pool shock, which adds a small amount of calcium to the pool when used. You can use Dichlor, Lithium, Non-Chlorine Shock or bleach as alternatives to Cal Hypo pool shock.

 

Another option, if your pool filter is set up for it...

 

"Calcium does not like warm water. As water temperature rises, calcium becomes more likely to precipitate out of solution. 

 

"Use a flocculant to attract the excess calcium and cause it to clump. After you use the flocculant, clean the walls and floors of your pool to remove the excess calcium and then backwash and clean your pump filter.

 

"Raising the pH to 10.0 causes dissolved calcium carbonate to come out of solution, or precipitate, clouding the pool. Allow it to settle, and then vacuum to waste. To use this method, you must have a means to bypass the filter by setting multiport valves to Recirculate, or removing internal cartridges/grids, to prevent clogging the filter with carbonate scale. You must also have a way to vacuum to waste, by setting multiport valves to Waste, or other ways to vacuum to waste, so a dusty layer of calcium scale can be vacuumed out of the pool. Then lower the pH back to normal use levels.

 

[DukSiam1]

Raise the temperature of the water above the freezing point.

[Beats56]

Trying to remember as I had two pools but think I used baking soda that I got in 50 lb bags. Only a couple of scoops. I am pretty sure that is what I used. Use to get it a local feed store.

[Lacessit]

You would need to purchase a water softener, and have it in line with your flow system. These are ion exchange resins or zeolites, which function by exchanging the calcium and magnesium ions for sodium. Ion exchange resins can be recharged by flushing them with concentrated salt or sodium hydroxide.

The other option is to use chelating agents such as EDTA or nitriloacetic acid. These don't remove calcium, but complex it so it stays soluble.

Not a good idea to try precipitating out with carbon dioxide to form calcium carbonate. The precipitate is so fine it will coat everything, including pumps and valves, and is very difficult to remove short of using acid.