Jeremy in New Mexico

[JeremyNMex]

Hi, everyone. I've been a pool operator for a few years, certified for a few months, and trying to grasp as much as I can ASAP. I'm certified in drinking water and wastewater systems also; there is a lot of overlap but much that's new to me as well. My pool is filled & heated w/ mineral water from two hot springs, with some flowthrough, so water chemistry gets complicated.

I'd love to hear from anyone else operating a mineral-water pool.

Jeremy

 

[chem geek]

Welcome to TFP!

You might be interested in Certified Pool Operator (CPO) training -- What is not taught.

Are you still using chlorine in your mineral-water pool? By minerals, I presume you mean primarily harder water with magnesium and calcium, correct? If that is the case, you treat it just like any other pool that has a higher Calcium Hardness (CH) level. If the minerals include other metals such as iron, then that's more like using well water and requires techniques to avoid metal staining. Some people use water filters for the fill water to remove metals while others use metal sequestrants and try to keep the pH somewhat lower.

If you get yourself a proper test kit (see Test Kits Compared), then you can give us a full set of water chemistry numbers.

 

[JeremyNMex]

Hi, chem geek. Nice to hear from you. I've been lurking for awhile and have read through both threads. I appreciate the info very much. The minerals in the pools are mostly iron and a bit of arsenic. The facility is more than a hundred years old, so there is a lot of folklore and imagination in what our guests hear. The pool itself is very old, and the plaster is permanently stained brown. That's the way the owner wants it...rustic (rusty?).

The pool is heated from a flowthrough from two hot springs (109 and 131 deg F), so there is a limited amount we can do with the chemistry. I (being colorblind) have a LaMotte ColorQ test kit. Our pH is 7.5 +/- 2, which is fine. TA is generally over 200, CH very low in the 20s. We chlorinate with trichlor in erosion feeders; the flowthrough keeps our CYA below 30.

I was thinking about looking into automated chlorination--currently we have to test every 4 hours. You folks have made me think twice about ORP controllers, though. Are there other options?

We also have 10 mineral baths which are not treated with chemicals, only ozone and UV. The guests think it's good that we don't add any chemicals; I don't. But we do empty and clean them nightly.

 

[chem geek]

Prominent makes various sensors that I describe in this post. Those chlorine sensors tend to be more expensive than ORP sensors. ORP isn't bad if you use it only for process control and independently measure FC now and then and reset the setpoint as needed. You need a pH controller as well.

As for the mineral baths with ozone and UV, it's a catch-22. To have disinfection in the spa itself to prevent person-to-person transmission of disease and to prevent pathogens from growing on spa surfaces where they never get circulated to the ozone or UV systems, you'd have to have ozone in the bulk spa water itself. However, doing that in a spa risks ozone outgassing and the EPA has strict ozone air limits.

 

[BoDarville]

Welcome to TFP!