NJPools.club Community

Hey y'all! ☕ First post of the day with my coffee in hand. I've got a Jandy Aquapure on my gunite pool here in Austin. My water looks crystal clear—seriously, you could read a book through it—but I keep failing the overnight chlorine loss test (OCLT). Algae keeps popping back up a few days after I shock. My test strips show chlorine, but something's off. Has anyone else in Texas dealt with this? Maybe it's the brutal sun eating up my chlorine before it can do its job?

**PatioPrince48**, clear water doesn't always mean clean water! I'm in San Antonio with a similar setup. The OCLT is telling you there's something organic in the water consuming chlorine overnight—likely algae spores you can't see yet. I've found that modern salt systems like the Aquapure can struggle if the chemistry isn't perfectly balanced. Have you checked your **cyanuric acid (CYA) levels**? If it's too high from stabilized chlorine products, it can lock up your chlorine, making it ineffective even if tests show it's present. Also, what's your phosphate level? Algae feed on phosphates.

Olivia's onto something, but let's get systematic—no guesswork. 💪 I'm in Dallas with a Jandy system on a gunite pool. Failed OCLT with clear water usually means nascent algae or other contaminants. Here's my routine: 1) Verify all test results with a **Taylor test kit**, not strips—they're unreliable. 2) Ensure pH is 7.4-7.6 and alkalinity 80-120 ppm. 3) Perform an OCLT correctly: test FC after sunset, no adding chlorine, test again at sunrise. If you lose >1 ppm FC, you've got something to kill. 4) Shock aggressively with liquid chlorine to 30 ppm FC, hold it there for 24 hours, and brush the pool thoroughly. The sun in Texas is a factor, but OCLT is done at night, so that's not the issue. Could be biofilm in your pipes too.

Thanks, both! ☕ Olivia, I haven't checked phosphates—good call. My CYA was around 70 last I checked, which I thought was okay? Ivy, I use strips, so maybe I'll invest in that Taylor kit. I did shock, but maybe not high enough or long enough. Could it be that my Aquapure's cell is getting old and not producing enough chlorine during the day to keep up, so the algae gets a foothold? It's about 3 years old. Also, with this heat, I'm running the pump 10 hours a day—should I increase that?

**PatioPrince48**, CYA at 70 ppm is on the high side—it can reduce chlorine's effectiveness. I'd aim for 50-60 ppm in a salt pool. For phosphates, if they're above 500 ppb, consider a remover. As for the cell, yes, age matters, but first, rule out chemistry. I prefer a more natural approach: after balancing, try **enzymatic cleaners** to break down organics without harsh chemicals. Also, ensure your filter is clean—gunite can trap debris. Run the pump during daylight hours when the sun is active to circulate chlorine. Ivy's shock advice is solid, but be patient; algae can hide in lightless areas.

Mila, 3 years is fine for a cell if maintained, but have you inspected it for scale? Clean it with a 4:1 water:acid solution if needed. Pump runtime: 10 hours might be low in Texas summer. I run mine 12-14 hours to ensure turnover. But first, **test accurately**. Get the Taylor K-2006 kit. If OCLT fails after proper shock and balanced water, consider: 1) **Ammonia contamination**—rare but possible from fertilizers. 2) **Mustard algae**—it's chlorine-resistant and common here. Treat with yellow-out if suspected. Post your full test results when you get them, and we can troubleshoot like a workout plan—step by step. 💪