Why Do We Have This Blue Powder In Our Salt Water Pool?by Suzann
Looking for an answer to my pool water issue. We recently switched from an ionizer pool filter system to a salt/sand filter and pump system. We are now having issues with a blue powder residue in the water and when water comes out of the vacuum it leaves this blue powder on the deck. Our pH and alkalinity are very low - overall hardness is very high. What can I do to properly treat my water and get it balanced for safe swimming!!?? Thanks! Thanks for the question Suzann Many times it could actually be the heater. Some heaters containing copper will leave a light blue residue or powder looking substance in some pools. Does it brush off or is it the color of copper? Your question says the pH and alkalinity levels are low, so this could be the issue. If the pH level is below 7.0ppm, you could be looking at copper stains in your pool. I would recommend that you take your water in to be tested for metals. If you don't have a heater, your fill water might be high in iron and copper. A metal sequastrant might be in order in you have a high metal count. Because metal sequestrants break down over time and get filtered and backwashed out, you need to weekly dose your pool if you have high iron and copper. Metal sequestrants that are based on HEDP, phosphonic acid or something similar are the most effective. Jack's Magic Blue, Purple, and Pink Pink Stuff, Metal Magic, Metal Free, & Metal Klear are very good. Adjust your pH to 7.6 - 7.8ppm and alkalinity between 80 - 100ppm. You need to check the salinity level of your pool as well. I've used a Myron Salt Meter for the last 3 years at the YMCA pool. You can call TMI Salt Pure and purchase it. They're based in WA state. Also ask for salinity water to calibrate your meter. For the hardness, you want to keep it between 150 - 250ppm. This is so the salt cell won't clog up and calcify. The only way to reduce water hardness is to drain 1/3 - 1/2 of the water and refill. There are no chemicals to reduce hard water. Calcium Hardness Saltwater Systems For Swimming Pools..High Calcium & Iron.. Here are some good links to my alkalinity and pH pages. They will show you the best way to make these adjustments: pH Swimming Pool pH Levels Pool pH Alkalinity Pool Alkalinity Total Alkalinity And the salt water pool pages: Salt Water Swimming Pools Chlorine Generator There's also good information on the pool Q&A pages for salt pools and chlorine generators: Swimming Pool Questions and Answers Hope this helps and have a fun and safe swimming season. Robert Follow Up Comment: By: Suzann Date: June 8, 2011 This is fantastic information - thanks so much - Great website too! |
