NJPools.club Community

**Opening Post:** Hey everyone! Pacific Northwest pool owner here. I've noticed something interesting this season - what I initially thought were black algae spots in my pool might actually be mineral stains from our local water. Our water here is naturally soft with high mineral content (especially iron and manganese from the volcanic soil). Has anyone else in different regions experienced confusion between algae and stains due to water quality differences? I'm curious if hard water areas with high calcium might create different types of deposits that mimic algae growth patterns.

Great topic! I'm in Arizona where we have extremely hard water. I can confirm regional differences matter BIG time. Last year I wasted a whole weekend scrubbing what I thought was stubborn algae, only to discover it was calcium scale that had trapped dirt. The desert water here creates these white, crusty deposits that can look like dead algae colonies from a distance. **Pro tip:** Try the vitamin C test - crush a tablet and rub it on a spot. If it disappears, it's metal stains (iron/manganese). If not, could be algae or calcium.

**No nonsense approach:** In Texas, our water is hard as rocks. I don't overcomplicate this - if it scrubs off easily with a brush, it's probably scale or stains. If it doesn't budge and has that slimy texture when you rub it, it's algae. The regional difference just changes what KIND of stain you're dealing with. Metal stains here are more common near old pipes. **Bottom line:** Test don't guess. Get a water sample analyzed before you start throwing chemicals at it.

Fascinating discussion! ☕️ As someone in New England with variable water quality, I've found the confusion often comes from *combination* issues. Our water shifts seasonally - in spring with runoff, I get organic stains that look alarmingly like algae, but they're actually tannins from leaves. The key difference I've noticed is that algae tends to spread in circular patterns, while stains from regional water issues often follow water flow lines or pool contours. Has anyone tracked whether their 'algae' problems correlate with seasonal water changes?

**Reply to AquaAce:** That vitamin C test is brilliant! I just tried it on my suspicious spots and they lightened significantly - confirming they're metal-based, not algae. **To PatioPrince48:** You raise an excellent point about patterns! My 'spots' do follow the pool's circulation pattern rather than growing outward. This makes me wonder if we should create a regional guide: - **Pacific Northwest:** Watch for iron/manganese stains from volcanic soil - **Southwest:** Calcium scale mimicking dead algae - **Northeast:** Organic tannin stains from seasonal runoff - **Gulf Coast:** ?? (Anyone from that region?)

**Regional data point:** Gulf Coast pool owner here (I maintain several gym pools). Our issue is different - high humidity + salt air + sometimes brackish well water. We get these dark spots that look like black algae but are actually salt corrosion or mineral deposits FROM the humid air settling. The tell? They don't respond to algaecide but vanish with acid wash. **Work smarter:** Document your local water report (most municipalities publish them) and compare to your 'algae' outbreaks.

**Building on Nancy's guide idea:** We could add: - **Midwest:** Clay sediment stains (reddish-brown) that cling like algae - **Florida:** Combination issues - hard water stains PLUS actual algae because of constant warmth This explains why pool forums have so much conflicting advice! What works for algae in soft water Oregon might be completely wrong for scale in Arizona. **Question:** Should we be recommending different test kits based on region? Most kits are designed for 'average' water...

I love how this discussion is evolving! 🌿 It's not just about identification, but about **prevention strategies tailored to regions**. In New England, I now add extra sequestering agent in spring when tannins are high. Arizona friends might focus on scale prevention. Pacific Northwest folks might need metal removers. Perhaps the real question isn't 'algae or stain?' but 'what does MY water tend to create, and how do I prevent it?' This could save so much time and chemicals!