Clean Water Made Easy Podcast
Podcast Q&A 10: Should I Use Phosphate To Treat Corrosive Water?
Hello. Welcome to the Clean Water Made Easy Q & A. My name is Gerry Bulfin. I’m a WQA-Certified Master Water Specialist and Water Treatment Contractor. Every week on our main podcast we delve deeper into the various well water treatment systems and problems. I also do these quick Q & A episodes because we get a lot of phone calls, emails, and chats every day and we get a lot of interesting great questions. Some are really good to share with others.
Today, we received an email from Jim who wrote: “We got blue stains on our sinks and bathtub and a neighbor told me to use a phosphate filter. I understand our well water is acidic and I’m wondering how the phosphate works and will it fix the acid water at the same time it’s helping my pipes.”
Okay, Jim, that is a very good question and phosphate is often used for corrosion. It doesn’t do anything for the acidity but the most common way we use phosphate for homes is in a crystal form. So it’s hexametaphosphate, actually, it’s sodium hexametaphosphate. So you are adding a little bit of sodium into the water. What happens is it looks like standard water filter housing, maybe like 12 inches high by 4 inches diameter, then usually ¾ of an inch pipe size.
Inside it has a little canister that’s filled with these somewhat clear-looking crystals of phosphate and when the water flows through a tiny bit dissolves into the water. What phosphate does in copper pipes, after awhile, even sometimes after a few days of running the water, is you’ll get a microscopic coating of phosphate on the pipe. Copper corrosion is really almost like setting up a weak battery in your pipes. There are different corrosion cells and electrons flow from one cell to the other. What’s going on is by coating the inside surface of your copper pipe it seals off that corrosion activity and either stops it or really slows it down.
It can immediately help a lot with preventing corrosion. It needs a little bit of hardness in the water. It doesn’t work on zero soft water, it likes a little bit of hardness because that’s how it’s putting down a sort of a layer of the compound where the phosphate and the calcium form to seal off the surface. When it’s working it’s a layer and it stops or slows down the corrosion. But it doesn’t do anything for the pH so if you have acidic water, you could still get problems with the water heater and get problems with fixtures and you can still get corrosion.
It could help but it’s usually if you know you have acidic water, you’re better off fixing the acidity. That’s what we recommend to folks. However, the phosphate feeders are much less expensive than neutralizers. Feeders are easy to put in and can be a short-term way to help. The other thing is for folks that have really corroded pipes and you’re fixing the pH with a calcite neutralizer which raises the pH and stops the corrosion by neutralizing the pH. Then a lot of times we’ll combine the phosphate; we’ll put it into a phosphate cartridge after the neutralizer. For some folks use it for say 6 months and that will really help with the corrosion. Later you can try removing the cartridges leaving your filter housing there. Or putting in a cartridge filter, like a 5 micron or 10 micron, on a temporary basis.
Anyway, that’s a really good question and generally, we do recommend them under certain circumstances. But, they’re not recommended for fixing the acidic water. They are put in a low enough rate so the water is drinkable but you’re drinking some phosphate but it’s not considered toxic. These things are NSF-certified for drinking water.
They do work as long as the water has a little bit of hardness in it. It is put on for your hot and your cold. You put it in your cold water and it seals all the pipes in the house.
Okay. Well, if anybody else has any questions, please go to our website cleanwaterstore.