• Please visit and share your knowledge at our sister communities:
  • If you have not, please join our official Homebrewing Facebook Group!

    Homebrewing Facebook Group

Is copper immersion chiller turning my pool green?

Homebrew Talk

Help Support Homebrew Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
If you want nice, clear water in the pool it's going to take some effort in warm weather.

The first thing you need to do is get all the foreign matter out of the pool. Use a net and set your pump to bypass the filter to vacuum out the junk. My 42k gallon pool suffers from pine needles, spruce, oak leaves, and pollen in the spring.
The important part is pH adjustment. The water needs to be at a pH level above 7.2, preferably closer to 7.6-7.8. Get soda ash (sodium carbonate), sodium bicarbonate, and chlorine in liquid, powder, and tablet forms. Soda ash and bicarb will adjust your pH UP and this is critical because it enhances the oxidation activity and life of the chlorine you'll use to sanitize the water. You can get your pool water tested at any Leslie's outlets for free and they can assist you with adjustments for pH, metals, and such. Flocculant is a necessary, too.
You may have to drain you pool periodically because the organic contamination is bad. I'm on city water and a total flush for 42k gallons can be expensive. Your filters need to be in prime shape and clean. The sand or diatomaceous earth needs to be replaced periodically because organic contaminants that don't get broken down in the "shock" oxidation phase can constantly come back to haunt you.

"Green water", in my opinion, means algae buildups and means your pH levels are out of whack. Soda ash and bicarb additions will help and once the pH levels are adjusted it's just a matter of "shock" with chlorine and run the pump continuously while doing constant pH checks with phenolpthalein red drops. Like I said before, I have problems with foreign contaminants in my water and one of the worst is pollen. It leaves a nasty yellow scum that is difficult to remove but can be cured with a working pool filter.
 
Last edited:
The dissolved chlorine content in pool water will change with pH levels and temperature. I have considered using the huge thermal mass of my inground pool as a great way to conserve water for brewing, but if you're recirculating pool water with a high level of free chlorine it would be a good idea to rinse the copper chiller out with simple tap water afterwards.

A low level of stable soluble copper ions in pool water can actually be beneficial because it prevents algae. If your pool water is green it's usually from algae and foreign contaminants.
 
Yeah, I’ve thought about the pool for chill water too but it’s logistically an issue for me as the garage is a long way from the pool unless I go through the house, and that would get a veto pretty much immediately. It may still be worth it if I can work the right pump out.
 
Back
Top