Show-n-tell: Community Pool Test Numbers

JayBauman

LifeTime Supporter
Sep 5, 2014
617
Katy, TX
In the heat of yesterday's late afternoon sun, the kids and I left our pool and ventured across the street to our community pool, which is cared for by the HoA. Just for fun, I brought my TF-100 along to see what I could learn. This pool is relatively new and was put into service just about a year ago. Other than there being a bit of dirt/sand on the blindingly-white bottom, the pool looked great and the water was sparklingly spectacular. Then I started characterizing the chemistry:

pH 8.2
FC 3.0
CC 0
CH 475
Alk 90
CYA 75


I'm a bit surprised by the pH. I have a hard time keeping mine within range, but I don't think I've ever seen 8.2 since startup. CH is the most inexplicable. I assume they use the same water that I do, and I have to add a fair amount of minerals to keep my calcium levels correct (fill water ~150 or so).

Since I know what I'm talking about (Thanks TFP!!!), the most concerning thing to me is the chlorine/stabilizer ratio. I would be targeting a minimum of 5-6 with CYA at 75, but the pool looks great. Is it correct to assume that 3.0 is high enough for disinfection? I'm assuming that they're using some sort of algae treatment to keep the pool looking so great with such low FC levels.

Anybody else take their chemistry fun set over to their local public pools and see what's happening?
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
49,057
Tallahassee, FL
Just think.......the PH could be OVER 8.2

The CH could be from the plaster if it really that new.

The FC and CYA could be a problem BUT what was it first thing in the morning and during the night. The FC of 3 in the late,hot,high bather load could explain the 3.

Kim
 

Donldson

TFP Expert
LifeTime Supporter
Jun 12, 2009
5,132
NW Ohio
That FC should be alright at 75 CYA to disinfect, bacteria and viruses are killed at much lower chlorine levels than algae. Not that I would want to get in if it was full of people. You are probably right, I would say either algaecide or phosphate remover.

I can't test public pools, it would just cause me to pull my daughter out of it in terror. I don't want to be "that guy."

From my HTC One via Tapatalk
 

zombiejeep

Active member
Jun 17, 2015
39
Nebraska
....I can't test public pools, it would just cause me to pull my daughter out of it in terror. I don't want to be "that guy."....

Same.

Still very new to TFP, but I know just enough to be dangerous. I would hate to know what we were swimming in!
 

JayBauman

LifeTime Supporter
Sep 5, 2014
617
Katy, TX
The FC of 3 in the late,hot,high bather load could explain the 3.

No problem with bather load. This was late afternoon, heat index 108°. I've never seen any more than 1 person at a time in our community pool. (That's my twins getting ready to jump in the "deep" end....)

Community Pool.jpg

- - - Updated - - -

Kind of like having the opportunity to inspect the kitchen at your favorite restaurant. Some things are better left un-seen.

I don't want to be "that guy."

The community pool opened up in May. I've been able to resist the urge to take my test kit over for the last 3 months. Yesterday I succumbed to the temptation. Time to hop back on the wagon....
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
Or they could be lucky that their water is low in algae nutrients and that they don't have phosphates in the fill water with lots of evaporation and refill. There are many pool owners who use Trichlor regularly, have high CYA, don't use supplemental products (e.g. algaecide or phosphate remover) and don't have problems in their pools. That's why they don't always believe what we talk about here. It is not necessary to use algaecide or phosphate remover to have pool water that doesn't grow algae quickly in spite of low FC/CYA levels; it can be naturally (initially) low in algae nutrients.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
10,041
SW Indiana
Pool Size
21000
Surface
Vinyl
Chlorine
Liquid Chlorine
My bet is they shock it regularly with cal hypo. Lets them get away with the lower chlorine level and explains the high calcium level.
 

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mickey4paws

Bronze Supporter
LifeTime Supporter
Apr 10, 2009
743
S.E. MI
Looks like a nice pool and big. Maybe the PH is so high because of those 3 water jet thingies? We have a nearby community pool but I'd be too afraid to find out what the chemistry is. You're brave, Jay :) I think I've turned into a snob. Ever since we got a pool, I won't swim in a public pool.
 

JayBauman

LifeTime Supporter
Sep 5, 2014
617
Katy, TX
Looks like a nice pool and big. Maybe the PH is so high because of those 3 water jet thingies? We have a nearby community pool but I'd be too afraid to find out what the chemistry is. You're brave, Jay :) I think I've turned into a snob. Ever since we got a pool, I won't swim in a public pool.

Your point is exactly why I decided to test the water. Sometimes the family likes to go over to the public pool (beats the heck outta me as to why!), so I wanted to see what we're getting into over there. For the single data point that I now have, the water seems to be OK for swimming.

So here's the funny part. I have an SWG, and sometimes I get tired of the salty taste of my pool water. After swimming a few laps in the community pool (decidedly NOT SWG), I realized the water has such a "flat" taste. I couldn't wait to get back to my backyard paradise for the salty taste and silky feeling. I guess TFP has made me into a pool snob.
 

eqbob

Well-known member
Jul 25, 2012
436
Central Texas
Sidebar...I was swimming last week in Jamaica and Cozumel and was longing for the 'normal' salt water taste rather than the stuff that burned my throat. ;)
 
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