Easiest Way How To Lower Calcium Hardness In Pool

calcium stains on the blue tile of a pool

When your pool chemistry is balanced, it feels like everything is in tune.  However, when you have one reading that’s constantly off the charts it can feel like an impossibility to rein it in.  When that reading is calcium hardness, it can seem like a hopeless task.  You search and you search, and you just can’t find a calcium hardness reducer chemical anywhere.  So you are stuck wondering how to lower calcium hardness in pool?

What Causes High Calcium Hardness?

The first issue with calcium hardness is the water you refill your pool with.  In some areas like the Texas hill country around Austin, the bedrock is limestone.  All the rainwater percolates down through the limestone before being sucked back up by your well.  This means your water is calcium rich from the start when you refill your pool.  

Over time as your water evaporates in the summer heat, you are losing distilled water into the air. The minerals dissolved in the water are left behind, increasing your calcium hardness.  

#1 Way How To Lower Calcium Hardness In Pool

When looking at the ‘how’ in how to lower calcium hardness in pool, there’s really only one way. You need to remove liquid water from the pool and refill. Unfortunately, unlike other water chemistry issues like lowering alkalinity in a pool, lowering calcium hardness is a commitment.

Now, its not so easy as to drain the pool completely and refill.  Yes you could do that, but that’s inherently risky.  Especially if you live in an area with a high water table.  Draining your pool could potentially ruin your pool completely. 

All too often inexperienced contractors will do just that and pop pools right up out of the ground.  Pools will float like a boat if the groundwater table is high enough when the pool is empty. 

In modern pools built in areas with a high water table, there is usually a hydrostatic release valve incorporated into the structure as a means to mitigate the risk. However, these cannot be relied on 100% as they can clog and fail as well.

poolside image of how to lower calcium hardness in pool with lowered water levels on a calcium stained blue tile pool spa combo in a backyard

How To Lower Calcium Hardness In Pool Step By Step

Now you know that you will be draining your pool to lower calcium hardness. What if you’re not confident in doing this? Don’t worry, we will walk you through step by step.

Step 1: Drain Out 2 Feet Of Water And Test

When considering how to lower calcium hardness in pool by draining the pool you must start simple.  Begin by draining out only 2 feet of water, then refilling.  Balance the water and test for calcium hardness once again.  You should be back in a reasonable zone.  If not, drain another two feet out of the pool and refill, and so on. 

Step 2: Consider A Water Truck Refill

If your refill water is especially hard, consider paying to have pool water trucked in to refill your pool.  However, be sure to ask the calcium hardness of the water you are buying. You want to be sure it’s an improvement over the water you would use from your tap.

Pro Tips For Refilling Your Pool Water

Additionally, it’s important whenever you refill your pool from the hose to consider your water source.  If you have a well, it’s not usually recommended to refill your pool from the well.  You may run the well dry, silt the well, or otherwise damage the well by drawing down the water level too low too quickly. 

Furthermore, sometimes your well water contains high concentrations of iron, copper, or other unwanted minerals.  These minerals may not impact water chemistry when topping off the pool from evaporation.  However, they may have a big impact if you refill with two feet of well water.

If you are refiling from municipal water, check with your water provider to see if they have discounts for when you fill your pool.  Often sewer bills are based on your water bill. It’s far easier to put a water meter on a house than a sewer meter – yuck.  Sometimes if you are refilling a pool, your utility company will credit you back the sewer portion of the bill if you tell them you are refilling a pool.

How To Lower Calcium Hardness In Pool Summary

You now understand that there’s only one way to lower calcium hardness. To solve your problem, you’ll need to drain some amount of your pool water. You can start small, draining only two feet of water. However, you may need to drain the pool completely. Use our tips to avoid floating your pool and ensuring the new water will be helpful.