Sanitation in Phoenix metro area

[jorgeL]

I live in the Phoenix metro area and I wonder how other owners in this or similar areas keep their pools sanitized, mainly between liquid chlorine and trichlor tabs. The service company that I was using to maintain my pool only used trichlor and it seems that a lot of people that I talk to in this area do the same. If using trichlor tabs how high do you let your CYA go? If you use liquid chlorine how often are you adding it to the pool in the summer months? Here are my latest results from my K2006 TK.

Free Chlorine: 4
Combined Chlorine: 0
PH: 8
Carbonate Alkalinity: 67 [67=125(TA)-(0.36x160)]
CYA: 160
Calcium Hardness: 225

I am out of chlorine tabs in my floater so I do need to add something soon. By the way, last week (8/20/19) my free chlorine was 9.8 so I am assuming that I am loosing about 1ppm of free cholrine per day. I would appreciate the help.

 

[Arizonarob]

Hi neighbor, welcome to TFP.

I can tell you that a complete drain and refill is in your future. With a CYA of 160, there is no way to be cost affective in keeping your FC in the range it needs to be.
For now, ride out the rest of the season with floating pucks, then plan for the drain around Nov to Feb when the temps are cooler, and the sun is off angle. (You don’t want exposed plaster/pebble with temperatures above 75-80)

Is your test kit a Taylor K2006C? (The “C” is important)

In the meantime, start reading up on how to properly care for your pool.

ABCs of Pool Water Chemistry

FC/CYA Levels

Pool School

 

[Jimrahbe]

J,

You should look at converting to a saltwater pool... No tablets or adding liquid chlorine are needed. Saltwater pools have a Saltwater Chlorine Generator (SWCG) which uses the salt in the water to make all the chlorine your pool will need.

We have a lot of members in the AZ area that have saltwater pools..

Thanks,

Jim R.

 

[proavia]

Welcome to TFP

When was the last time the pool was drained? You may want to double check your CH result of 225 - that's about the CH of our tap water here in the Chandler/Gilbert area. Since you reported a CYA of 160, the water in the pool has not been recently drained - water has only been added do to evaporation. CH doesn't leave the pool with evaporation - so the CH continues to increase.

List the steps you did to test CYA and CH.

No need to report Carbonate Alkalinity - just report the TA. Also, use PoolMath and the FC/CYA Levels

Report your results in the following format to make it easier for us to read... (Temp is water temp)
FC
CC
pH
TA
CH
CYA
Temp

It would be best to use liquid chlorine. Walmart has Pool Essentials 10% (Home Depot & Lowes too) A&M Corsons (McQueen & Warner) has 12.5% in a 4 pack of refillable gallon jugs. If your CYA is 160, the FC should be around 12 (FC 7.5% of CYA).

Going forward - whether you choose to use liquid chlorine or install a SWG - you will still need a full drain/ refill after the weather cools down.

 

[jorgeL]

Thanks all for the inputs. Here are the replies to your comments/questions:

Rob:
Thanks for the links. I find pool school to be very easy to understand and the approach seems very doable.
My test kit is a Taylor K2006, just the 3/4oz bottles, no C in the name.
A couple of questions:

• Why wouldn't it be cost effective to keep chlorine levels in the range that it needs to be?
• Why use trichlor pucks instead of liquid chlorine for the rest of the season?

Jim:
Yes, we would like to convert to salt water but it is not in our immediate plans right now, maybe in a couple of years, hopefully sooner.

Gene:
Thanks for the list of places that sell liquid chlorine. I was planning to get mine at Lowes or Home Depot which are close to where I live. I'll have to go and check out A&M Corson's, I have not heard of them.
We just moved to this house in May and the pool was drained and re-filled then, so the water is about 4 months old.

• For CYA I used my Taylor K2006 test kit.
  • I had to do a 1:1 ratio of pool water with tap water (I followed the steps in the "Extended Test Kit Directions" for CYA) because the dot was not visible before the level got to 100 when I used only pool water. The dot in the bottom disappeared around 80 when I did the 1:1 ratio mix so that is how I got to 160.​
  • Since I am new in doing this I took a water sample to poolwerx and they came up with 167 as my CYA.​
• For CH I am relying on poolwerx and Leslie's results.
  • I have done the CH test twice with my test kit but I am getting results of 380 and 425. I am getting a fading endpoint in the CH test (sample turning purple) and I do add 5 drops of the titrant at the beginning and that is how I got 425 but I may need to repeat the test.​
  • Nevertheless, since my water is 4 months old I feel more confident in the 200ish number that I am getting from Leslie/poolwerx. I've taken water to them 4 times now and the CH is about the same, around 200.​

A couple of questions for you:

• Why report only TA instead of Carbonate Alkalinity? I thought that I needed to make the adjustment based on my CYA.
• So would it be ideal to keep my FC level at 12 at all times?

 

[proavia]

I think the 380-425 is much more believable than 225 - but even 425 may be low. Here's why - your refill water (if not run thru a water softener) is around CH of 200-250 with a TA of around 110 (this is going by my refill water in NE Chandler - yours is probavly close to mine). Let's say your pool has evaporated only 1/2 inch of water per day for 160 days (4 months). That's 80 inches of evaporation - probably more than half your pool depth. So, if you lost half your volume to evaporation (and remember, the CH doesn't evaporate with water evaporation), you hafe at least doubled your CH in 4 months. 1/2" of evaporation per day during the summer in our desert climate is quite reasonable.

We use TA here because PoolMath take the CYA into account automatically. Hopefully you are using PoolMath and not that Taylor "water wheel" thingy - PoolMath is so much easier

Honestly, Poolwerx and Leslies results are worthless - and you're not apt to get quality replies here when using PS test results. I'd believe your own test results from your K2006. Even the place I mentioned isn't real great at testing - but their refillable 4 packs of chlorine and acid are priced pretty good and the chlorine is always fresh (no date codes, but they get a shipment twice a week directly from the manufacturer - HASA. If you go to HD or Lowes, be sure to check the date codes - a lot of their stuff is old and sits outside in the heat. Walmert tends to have theirs inside - but check the date codes...... 19180 is 2019, day 180 - roughly near June 30th. You definitely want stuff produced in 2019 and the higher the last 3 digits the fresher it is.

An FC of 12 would be the minimum for CYA 160. You may be better to dose to about 16 to buffer yourself from daily FC loss (which can be 2-4 ppm per day in a properly sanitized pool this time of year). Realize that your pH will read falsely high with FC above 10 - so it's going to be a challenge testing your pH.

Hopefully others will be along to give you some ideas on how best to manage your pool water until you can do a water exchange. Maybe @mknauss will have some input as he battles CH regularly.

 

[Arizonarob]

Why wouldn't it be cost effective to keep chlorine levels in the range that it needs to be?

Just to give you an example. In my 11k gallon pool with a CYA of 70, (I run high CYA in the summer to help with FC burn off) I use a quart a day of 10% chlorine to keep FC around 8.
With your CYA of 160 in 8k gallons, (Are you sure your pool is only 8k?) you will be using gallons of 10% a week to maintain the correct FC level in your pool.

Why use trichlor pucks instead of liquid chlorine for the rest of the season?

At this point with CYA so high, it’s just easier to coast through the rest of the season till you can drain and refill.

I was planning to get mine at Lowes or Home Depot which are close to where I live.

As Gene mentioned, HD & Lowe’s tend to keep their chlorine in the outdoor garden section, which is not good. (Even when they keep it inside, it’s just been moved from the outside.)
I buy mine at Wally World in 2 pack boxes. Always kept cool, and fresh dates. (I shop the Walmart on Gilbert rd by the 202.)

 

[jorgeL]

I think the 380-425 is much more believable than 225 - but even 425 may be low. Here's why - your refill water (if not run thru a water softener) is around CH of 200-250 with a TA of around 110 (this is going by my refill water in NE Chandler - yours is probavly close to mine). Let's say your pool has evaporated only 1/2 inch of water per day for 160 days (4 months). That's 80 inches of evaporation - probably more than half your pool depth. So, if you lost half your volume to evaporation (and remember, the CH doesn't evaporate with water evaporation), you hafe at least doubled your CH in 4 months. 1/2" of evaporation per day during the summer in our desert climate is quite reasonable.

Gene, this makes sense. My pool is 5 feet in the deepest part so CH may be over 400. I ran the CH test again today and got 390, I will get the speedstir and try with that.
I do use poolmath, both in my phone and in my laptop, depending on where I am at.
Thanks both for the advice on liquid chlorine, I was not aware of the storage places in HD and Lowes and the expiration dates. I have a Walmart close by at Power and Ray from which I could get the chlorine.
Rob, as far as I can tell, yes, the pool is around 7k gallons. It is an odd shape so I had to divide the pool in 1 foot strips and measure length and depth of each strip and add them all up to get a more accurate volume.
I'll keep you posted on what I decide to do. Thanks again, this has been super helpful.

 

[proavia]

Jorge - try using a 10ml sample of pool water. It will save on reagents and is close enough for our needs.
Each drop of R-0012 will be 25 ppm CH.

Calcium Hardness

A drop-based test that measures the hardness in your water. Once measured, it is used … Read more…

www.troublefreepool.com

Using a SpeedStir will improve the overall accuracy of your testing. Be sure to hold all reagent bottles completely vertical and let the drops fully form on the dropper - about one drop per second is a good dispensing rate.

Do you have a water softener? If so, using soft water plumbed to your autofill or coming out of your hose will help keep the CH in check.

Using liquid chlorine will allow your CYA to remain relatively stable. A level of 40-50 CYA will work well in the valley - and still leafes a bit of room to use trichlor (3" pucks) if you are out of town and have no one to add liquid chlorine in your absence.

 

[jorgeL]

A quick update: I've been adding liquid chlorine twice a week and it's going great.