My swim club indoor pool results

[Ronald U.]

I know TFP is not for commercial pools, but can anyone make sense of the results I got today from my indoor swim club lap pool? I do not know what systems they use. Thanks.
pH > 8.0 (strange color)
FC 26.0
CC 5.0
TA 90 (strange color)
CH 375 (color also mildly atypical)
CYA 0

 

[needsajet]

Hope ya wear goggles!

 

[MarianParoo]

TFP says you cannot test pH reliably with an FC over 10ppm. No comment on the rest. You swim there?

 

[JamesW]

The strange colors are from the high chlorine levels. Trying to manage a high use indoor pool with only chlorine is usually a losing battle.

The ph will look purple/violet and the TA will go from blue to yellow instead of green to red.

 

[Patrick_B]

The high FC is changing your TA test color, and your pH test as well. The FC is very excessive especially in the likely case where there isn't any Cya/Stablizer in the pool. I won't say its going to cause anything drastic, but I wouldn't suggest swimming in it. For an indoor public pool, it is without question far outside normal regulations. May I ask why you are testing?

TFP says you cannot test pH reliably with an FC over 10ppm.

As for the pH, TFP defaults to what the maker of the kits (Taylor Technologies) we usually suggest using, and they say greater than 10.0 PPM FC is an interference. It isn't something we just made up on the fly. See the link to Taylor's site below.

Potential Interferences

 

[Ronald U.]

Thanks for all the input. I am testing because I am a curious fellow.

 

[JamesW]

What is the pool volume and how many swimmers per day?

 

[Ronald U.]

Rough guess 60k gallons and several dozen swimmers per day. It is a 25 meter, 3 wide-lane lap pool, average depth 4 feet.

 

[JamesW]

Seems like extra high CCs for that much use. Maybe they're using MPS.

 

[JoyfulNoise]

Seems like extra high CCs for that much use. Maybe they're using MPS.

Agreed. If MPS is being used, it would show up as additional drops of R-0871 titrant on the DPD-FAS test. Hard to say why the CCs are so high but, being an indoor pool with no UV light, it's not that unreasonable. I can't imagine anyone could be comfortable in that water, the CCs alone are enough to induce coughing.

 

[Ronald U.]

Thanks, all. I know nothing of MPS but I will read about it. / I must be acclimatized because I've been swimming there 3x/week for years. And the odor seems minimal. Of course, nothing like my TFP, don't you know!

 

[JoyfulNoise]

MPS = potassium monopersulfate = non-chlorine shock

 

[JamesW]

Any chance that they use bromine?

 

[Patrick_B]

Given the pool type/situation, I too think the CC count is more than plausible. I obviously have no idea what they plan, but I would think MPS would be unlikely due to cost factors. That's being presumptuous about their budgeting motives to be sure and ignorant of club pool management as well. It would not be surprising to find that the pool balance/chemistry is poorly managed and monitored as a rule. Maybe they had an off week or day, or maybe this is their "normal" or close to average. Perhaps they have a UV or Ozone system that is down? Rampant speculation of course, but it has me curious enough.

Not much else exciting happening in December. :santa:

 

[JoyfulNoise]

One other question would be - how long was it between the time you drew the water sample and when you did the testing? Leaving pool water in a sample container for too long can cause all sorts of weird results. But i agree with Patrick_B it's the slow season around here....

 

[Ronald U.]

Pool water was in a capped bottle for about 6 hours.

 

[JoyfulNoise]

Pool water was in a capped bottle for about 6 hours.

Yeah, that's not good. Still it's unusual to have high FC like that but leaving pool water in a bottle for more than 30mins to an hour is not ideal. CCs can form from the FC reacting with the bottle material and build up because there's no where for them to go.