10 pct Liquid Chlorine as a Chlorinator

[Reed Kadavy]

I started using 10pct liquid chlorine from Home Depot in my 13,500 gal pool in new water on Dec 1st. So far I have gone through 11gal. With the help of solar my pool temp is in the low 70's. What is a rough estimate of the increase in chlorine use when the pool temp reaches the mid 80's? I'm trying to weigh costs vs converting to salt.

 

[mknauss]

Did you check the dates on the bleach from HD? They are notorious for having old and degraded bleach. Look for a number like 17XXX or 18XXX. Should be less than 60 days old. Also, HD stores it outside, not a big deal now, but in the summer, not good.

You will typically use 3-4 ppm of FC each day in the summer (May - Sept). More on high bather load days. My little pool here in Laughlin reaches 5 ppm in July.

 

[bmoreswim]

Reed - What is your current CYA level? That will also affect how much FC you go through.

MK - What CYA level do you run your pool at in season in NV for reference?

 

[JoyfulNoise]

I used all of 80oz of 8.25% bleach these past 2-1/2 months. My water was cold, as low as 48F, but my FC loss rate was minimal.

To the OP - converting to an SWG just means you are buying all of your chlorine up front. There is no economic difference between bleach versus an SWG. The only hard part is the upfront cost incurred. Being in AZ I would say you should convert to salt. It is A LOT easier to manage a pool here when you’re not having to jug-dump everyday.

 

[mknauss]

I keep my CYA at 70ppm plus or minus.

We have daytime temperatures of 120f plus at times during the summer.

 

[JoyfulNoise]

I keep my CYA at 70ppm plus or minus.

We have daytime temperatures of 120f plus at times during the summer.

Marty,

I know we’re not here to discuss your pool, but hopefully what I say has some use for the OP. I know when my CYA gets low because I see my daily FC demand go up. My pool, even in 120F Tucson heat, uses 1-2ppm/day. As you know I am the “tinkerer” on this site always fiddling with my chemistry but one thing I learned about my pool is that it prefers to have its CYA at a minimum of 80ppm. When it goes down to 70ppm, I see the FC loss rate go up. Last year I kept the CYA at 90ppm. All that is ok for an SWG pool but I have found that CYA levels make a big difference in chlorine stability given the uniquely hot and high UV environments we live in.

 

[Reed Kadavy]

My CYA is 30. I was using tabs and that's why I dumped 2 yr old water end of Nov 2017. My CYA at the time was over 200.

 

[Reed Kadavy]

I have been watching bleach dates. Box I am currently using is 17-334. Sounds like I will be putting about 48 oz in each day during the summer while I am currently putting that amount in every other day.

 

[Reed Kadavy]

I re-tested my CYA and I'm somewhat below 30. How high should I go and is there a way to determine how much Conditioner to add? One gallon originally brought the CYA level up to 30 with the new water.

 

[JoyfulNoise]

In our part of AZ, you’ll need at least 50ppm CYA to keep the UV loss down. But I bet you’ll be raising it higher than that once the summer heat kicks in.

Since it’s winter, I would say you should get yourself a blue chemical floater and load it up with a few 3” trichlor pucks and put that in your pool. You need the FC and CYA, so there’s no harm in using trichlor. The 3” pucks are about 8oz by weight each so you can plug that into pool math and it will tell you how much CYA each puck will deliver.

Use ONLY 99% trichlor pucks, not those multichemical pucks that you find in places like Costco. Pool Stores will be happy to sell you a 10lbs bucket of pucks or whatever their smallest size is.

Trichlor is acidic so you will need to monitor your TA closely.

 

[Reed Kadavy]

Thanks for the advice. I have both pucks and Conditioner on hand, but using the pucks would certainly be the cheaper way to go.

 

[triptyx]

Yes, if you're raising CYA anyhow, may as well use some pucks.

 

[mknauss]

Marty,

I know we’re not here to discuss your pool, but hopefully what I say has some use for the OP. I know when my CYA gets low because I see my daily FC demand go up. My pool, even in 120F Tucson heat, uses 1-2ppm/day. As you know I am the “tinkerer” on this site always fiddling with my chemistry but one thing I learned about my pool is that it prefers to have its CYA at a minimum of 80ppm. When it goes down to 70ppm, I see the FC loss rate go up. Last year I kept the CYA at 90ppm. All that is ok for an SWG pool but I have found that CYA levels make a big difference in chlorine stability given the uniquely hot and high UV environments we live in.

I agree with the 80 being best. But I know I probably average about 70 as it degrades pretty quickly. We are also gone for fairly long stretches of time and thus the CYA level goes down. Pool service I will only let add acid and clean the pool.

Thanks for the input.

 

[Reed Kadavy]

I am 5 months into my experiment shifting from trichlor tabs to liquid chlorine. The water is certainly more brilliant, but I am beginning to experience the amount of chlorine it takes to keep the chlorine level at an acceptable level as temperatures are warming.

I have a 13,500 gal pool. My CYA is at 80, PH 7.8, and I am using 10 pct chlorine from Home Depot at a little less than $7.00 for two gal. My water temp is close to 90 with help from solar heating and today was our 2nd 100 degree day in Gilbert AZ.

Chlorine use has increased the last week. To reach 8 ppm I added 69 oz two days ago and 86 oz today. The chlorine level dropped from 8 to 3 in the two days. At this rate it looks like I will probably be using about 2 gal a week through the summer.