NJPools.club Community

**Posted at 7:15 AM** Hey all, jumping in between meetings. I’ve got the same issue—my fiberglass pool in Massachusetts is testing high for CYA (over 100 ppm) but the chlorine readings are low and the water’s looking a bit cloudy. From what I’ve read, high CYA basically locks up your chlorine, making it less effective. I’ve been using stabilized chlorine tabs (trichlor) for convenience, but they add CYA every time. Might be time to switch to liquid chlorine or cal-hypo until we get this under control. Anyone else tried that?

**Posted at 10:30 AM** SwimSage33 is spot on! Weekend warrior here in Connecticut—I dealt with this last summer. High CYA is like putting sunscreen on your chlorine; it protects it from the sun so much that it can’t do its job. If you’re over 100 ppm, partial drain and refill is the fastest fix. I did about a 1/3 drain, refilled, and switched to liquid chlorine for a while. Also, check if you’re using pool store “shock” products—some are stabilized too. Test strips can be iffy; get a good test kit like the Taylor K-2006. Happy to help more!

**Posted at 2:45 AM** Night owl checking in from Maine. This is super common with fiberglass pools, especially if you’ve been using tabs or granular shock with stabilizer. High CYA (>80-100 ppm) means you need much higher free chlorine levels to stay effective—like 7.5% of your CYA level. So if CYA is 120, you might need FC around 9 ppm just to prevent algae. Liquid chlorine (sodium hypochlorite) doesn’t add CYA, so it’s a good short-term fix. But yeah, partial water replacement is the real solution. Don’t forget to balance pH and alkalinity after refilling!

**Posted at 9:00 AM** Skeptical mom here in Vermont. I’m always wary of quick fixes, but this one’s legit. My family pool had the same issue—cloudy water, chlorine doing nothing. Turns out, we’d been overusing stabilized chlorine for years. CYA doesn’t evaporate or break down easily, so it builds up. Draining some water is safe for fiberglass if you do it gradually (don’t empty it completely!). Also, watch for phosphates—high levels can feed algae even with chlorine. Get a professional test if you’re unsure, and maybe switch to a saltwater generator long-term to avoid CYA buildup. Stay safe, everyone!

**Posted at 12:30 PM** Quick update: Thanks for the tips, everyone. I’m going to test with a better kit this weekend and plan a partial drain. SlideStar, good call on the test strips—I’ve been using those, and they’re probably not accurate enough. HydroHero29, I’ll look into phosphates too. For now, I’ll pick up some liquid chlorine to boost levels without adding more CYA. Appreciate the help—back to my next meeting!