Do you have calcium concerns? No, we aren’t talking about nutrition but water chemistry! Calcium is a mineral that is common in Iowa tap water. If you’ve ever scrubbed hard water scale, you know how frustrating calcium deposits are. In pools and spas, unbalanced calcium will throw off your water quality.
This FAQ will tell you everything you need to know about calcium, why it’s damaging to pools and spas, and how to correct it.
And if you want to see a massive chunk of calcium that one of our techs had to chisel out of a pool heater, watch our Splashy Segment Calculating Calcium!
Q: What is the ideal range for calcium?
A: Calcium should be within 200-400 ppm (parts per million) for concrete pools and 150-250 ppm for hot tubs. You can use a normal test strip to get an accurate reading.
Q: Why are calcium levels so important?
A: Because calcium is naturally occurring, there’s no way to avoid it. Calcium affects whether water is too hard or soft – both of which create problems. It has to be just right, which is why it’s essential to always monitor water quality.
Q: Why is high calcium a problem?
A: Calcium that’s over 400 ppm will become a visible issue. It usually appears as stubborn scale that’s dingy white. It’s abrasive too, snagging bathing suits and scratching skin.
It will also collect on the insides of your pool or spa components. It can clog filters, making it more difficult to screen other particles. Calcium deposits can also decrease pipe diameter, creating pressure issues. Scale also acts as an insulator on hot tub heaters, making them less effective.
High calcium may also present as cloudy water. If you’ve shocked and added clarifier but the water’s still murky, calcium is likely to blame.
Q: Is it true your calcium can be too low?
A: Yes! Don’t let calcium fall below 200 ppm. Despite its name, soft water is actually corrosive. That’s because low pH means high acidity.
Acids love to create trouble. They can etch surfaces (metal and acrylic alike), irritate skin, dissolve grout and plaster, and pit concrete. They can even cause your hot tub heater to malfunction by eroding its metal parts.
Q: Yikes! How do I fix my calcium levels?
A: If it’s too low, simply add a calcium hardness product to your water. We recommend Brilliance Calcium Hardness for spas or X for pools. Make sure to follow the directions for your gallonage and retest afterward to confirm calcium is at the right level.
The fix for high calcium is more costly – drain and refill. It’s not a big deal with a hot tub (read our refresher on draining spas). But that process is harder and more expensive with a pool. That’s why your best option is to never let calcium get too high in the first place.
For more tips on how to stay on top of water chemistry: