Water Filter—Is Calcite Safe?

February 13, 2012, by Debra Lynn Dadd

Question from keelyeliz

Dear Debra,

Still trying to educate myself on a water filter for my family! (It's a tall order as there are SO many on the market!!!)

One of the contaminants in my water are nitrates. I just discovered this as I was looking through my city water report. In an instant, I switched from being a carbon block advocate, to loving the idea of reverse osmosis (I have always written reverse osmosis off, after reading that it removes essential minerals from the water, and leaves it with a low ph.

Anyway, even with these pitfalls, I'm now leaning towards reverse osmosis, because of the need to remove nitrates. I came across a filter by Pure Water Products that contains a carbon block pre-filter, a TFC membrane, and a calcite/carbon post filter (along with a multi pure unit). The company states that the calcite will raise the ph of the water after being lowered by the reverse osmosis unit.

My question is in regards to Calcite. I have never heard of this before? I'm wondering if you have, and if you know if it's safe, and effective at regulating ph?

Also, do you agree that reverse osmosis is essentially the only way to remove nitrates from water? Or is there another type of filter available?

Debra's Answer

Calcite is another name for calcium carbonate, a natural mineral.

Calcium is the main constituent of bones and teeth and it has keys metabolic functions.

Calcium is sometimes referred to as lime. It also assists the functions of nerves and muscles.

As with many other natural elements, calcium is essential in certain amounts and toxic if too much is taken. Lack of calcium is one of the main causes of osteoporosis, but too much calcium can lead to the development of kidney stones and sclerosis of kidneys and blood vessels.

Calcium itself is not toxic, but I don't know if running all your water through a calcium carbonate filter would add up to excessive calcium over time. I think unlikely.

Calcium is widely used to adjust the ph of water, making it more alkaline. One drawback is that calcium also makes water hard, and so then a water softener needs to be used.