Diatomaceous earth. That’s a mouthful, and it’s the reason everyone calls it DE. It sounds rather sinister, don’t you think? But it’s not. It’s quite common. Most people, whether they’ve heard of it or not, come in contact with it every single day! I’ll tell you about then I’ll tell you why it is so good for your swimming pool.
It was discovered about 200 years ago in Germany. A man was sinking a well on his farm and thought he found limestone. Instead of finding limestone, he discovered diatomaceous earth.
They are similar. Limestone is a sedimentary rock consisting mostly of fragments of coral. DE consists of diatoms. These are a fossilized type of single-celled, hard-shelled algae. You’d need a microscope to see them individually, but dead and compacted it’s DE, a soft rock that easily crumbles into a fine powder. It’s found all over the world in fresh and ocean waters, and on land–even in deserts.
The uses of DE are varied. Because it is a mild abrasive, it’s earliest use has been in both toothpaste and metal polish. Alfred Nobel in 1866 discovered that nitroglycerin was more stable and safer to handle when mixed with DE. Applied dry, it’s an insecticide. Completely safe for humans, it kills bugs because the powder is so fine it’s absorbed into their bodies and they dehydrate as they die. It’s put in many dry foods such as cereals and grains to kill invading bugs. It’s completely safe for humans to ingest.
The powder of DE is so fine it makes a terrific filter for liquids, including beer and wine, but mostly for water. It removes very fine particles including bacteria, though it doesn’t remove viruses. It also make a terrific filtering system for swimming pools. DE involves more work than a sand filter, but for the clearest, cleanest water in your pool, DE is the way to go.
DE makes cleaner water because it catches smaller particles than sand or cartridge filters, but it requires a little more work to maintain. Like the sand filter, you must backwash regularly. Don’t let the backwash water back into your pool or it will clog up the filter faster; run it into a different location. After you backwash you must add more DE through the pool skimmer. How much you add depends mostly on two things: manufacturer and how long you backwash.
DE is quite safe around people except for one thing: you don’t want to breathe it. Wearing a face mask helps, but DE particles are so fine that even the best commercial masks only help a little. The best strategy is handle it gently, and keep any blowing powder away from your face.
The DE filtering system for your pool is not terribly difficult to maintain, but before you start, I highly recommend you consult a pool professional for the cleanest, clearest swimming pool.