how low can I let FC go

[engrav]

Severe shortage of liquid chlorine around Puget Sound. Cities are scrambling.
I have 14 bottles and CYA is 40.
Pool Math says FC min 3 and goal 5-7.
Essentially no one is swimming (all off to camps) and pollen season over.
To maintain 5-7 takes about 1 gal every other day so 14 bottles about 28 days; maybe not enough.
How low dare I let FC go?
Thanks
Loren

 

[GenericHbomb]

Realistically FC around 3 is low as you can go

You could bring your CYA down which would lower your min FC but I dont know if the trade off is worth it. Someone with more knowledge would have to comment.

 

[zea3]

What is your CH level? You may be able to get some cal-hypo shipped and augment with that if your CH is not too high. If you use 43% cal-hypo a 16 ounce bag will raise FC by 2.3ppm and CH by 1.6 A 73% bag will raise FC by 3.5 and CH by 2.4, so if your CH is less than 500ppm you could use cal-hypo one day and liquid chlorine the next so you could stretch the liquid chlorine out without risking algae. This may also be a case where a little polyquat 60 algaecide could be a good preventative in case FC drops too low.

 

[Newdude]

This is an experiment that never reacts the same for anybody. You will be boldly going where your pool never went before. What I can tell you is that the closer you get to the minimum, the more often you need to test. Not being in target range to start generally puts you under minimum in less than a day. Possibly just a few hours on a hot day.

I don't envy your decision as you are between a rock and a hard place. What is your backup plan if it doesn't work out ? Ironically if saving the bleach fails, you'll need tons of bleach. Will you just close the pool and hope next year has better supplies ?

 

[revitup]

How does maintaining FC of 3 use less chlorine per day than maintaining 5 - 7?

 

[Newdude]

How does maintaining FC of 3 use less chlorine per day than maintaining 5 - 7?

FC burns off as a % based on the CYA. For the sake of this discussion let's say OPs FC is burning off at rate of 33%. At a 3 FC it is a loss of 1 PPM. At a 9 FC it would be close to 3 PPM Not usually a huge deal for most of us, but in a shortage when every drop counts, it matters.

It's certainly not the only factor but a higher FC burns off faster.

 

[revitup]

FC burns off as a % based on the CYA. For the sake of this discussion let's say OPs FC is burning off at rate of 33%. At a 3 FC it is a loss of 1 PPM. At a 9 FC it would be close to 3 PPM Not usually a huge deal for most of us, but in a shortage when every drop counts, it matters.

It's certainly not the only factor but a higher FC burns off faster.

Ok, I guess I knew that. I assumed he would adjust CYA to be in line with the new FC target.

 

[engrav]

CH is 330; so maybe cal-hypo alternate liquid chlorine is the deal.
I think I even have some cal-hypo in the garage.
Thanks for the idea.
Loren

 

[engrav]

True, have 25# of cal-hypo 73%.

So will start trying to bounce between FC 3 and 5 alternating ½ gal 10% chlorine and 9 oz cal-hypo.

Dissolved it in a bucket and it dissolves pretty quickly. Not many particles went in the pool. Surely is hard on one's nose.

Usually out here we pray for sun/no rain. Now gonna start praying for clouds/rain.

Thanks again for suggestion.

 

[reggiehammond]

$1400 and a few days and Discountsaltpool.com could have you a SWCG sitting your doorstep.

 

[GenericHbomb]

$1400 and a few days and Discountsaltpool.com could have you a SWCG sitting your doorstep.

Thats not bad. Pretty simple to DIY? Just a pipe in and small electrical line after sand filter right?

 

[reggiehammond]

Thats not bad. Pretty simple to DIY? Just a pipe in and small electrical line after sand filter right?

Yes - super simple. I did it in less than an hour.

 

[mguzzy]

If you get a lot of organic input from your overhanging trees going the minimum may be really pushing it. Just the dripping of rain off the leaves will add organics to the water. So, watch out. I like @reggiehammond 's idea of "the Lets use this as an opportunity to add an SWG"... you have a month worth of CL to make it happen, and then you are not beholden to the ups and downs of the CL manufacturing pipeline.

 

[engrav]

If you get a lot of organic input from your overhanging trees going the minimum may be really pushing it. Just the dripping of rain off the leaves will add organics to the water. So, watch out. I like @reggiehammond 's idea of "the Lets use this as an opportunity to add an SWG"... you have a month worth of CL to make it happen, and then you are not beholden to the ups and downs of the CL manufacturing pipeline.

thanks

Is true, algae bloom would be not so good with limited liquid chlorine.

But this is a low biomass time, no fir needles, no cherry petals, kids at camps, wind storms unlikely, etc.

And we have a ton of summer projects going so dunno if we could chin yet another.

I did order up some polyquat to add to the plan. And FC was 4 this morning. And dense clouds.

Don’t know much about SWG. I think I will call my pool contractor and discuss it.

Thanks.

Loren

 

[Newdude]

Don’t know much about SWG. I think I will call my pool contractor and discuss it.

As a reference to how strongly I feel about SWGs, we moved and are building again. I had my new SWG/controller sitting in my garage before I even inked the build contract. And it was not easy to secure with all the shortages.

*that* strongly about them.

 

[reggiehammond]

thanks

Is true, algae bloom would be not so good with limited liquid chlorine.

But this is a low biomass time, no fir needles, no cherry petals, kids at camps, wind storms unlikely, etc.

And we have a ton of summer projects going so dunno if we could chin yet another.

I did order up some polyquat to add to the plan. And FC was 4 this morning. And dense clouds.

Don’t know much about SWG. I think I will call my pool contractor and discuss it.

Thanks.

Loren

Don’t be surprised if your contractor is negative to SWCG. There’s lots of myths and misinformation out there.
I wouldn’t trade mine for anything.

 

[engrav]

Don’t be surprised if your contractor is negative to SWCG. There’s lots of myths and misinformation out there.
I wouldn’t trade mine for anything.

Was not negative; kinda neutral. Maybe thinkin' I would buy one from him. But he had chlorine for sale so I bought four 4-bottle packs so now have 16 more bottles. Like another month. Of course they are not in the garage yet.

 

[engrav]

In another thread am trying to deal with the liquid chlorine shortage. Advice was alternate liquid chlorine and cal-hypo to stretch the chlorine. Am so doing.

But a question.
Say I would like to add one gallon chlorine. ½ gal and 9oz cal-hypo would be the same chlorine dose and save ½ gal of the liquid.

Can I add liquid chlorine and cal-hypo at the same time?

thanks

 

[mknauss]

You can add them but not at the same exact time. The liquid chlorine should be added in a pencil size stream at a pool return with the pump running. The Cal Hypo should be dissolved in a bucket and poured at a pool return with the pump running. Same process, just at separate times.

 

[engrav]

You can add them but not at the same exact time. The liquid chlorine should be added in a pencil size stream at a pool return with the pump running. The Cal Hypo should be dissolved in a bucket and poured at a pool return with the pump running. Same process, just at separate times.

thanks
if at the same time same place, what happens?
if at the same time but the opposite return, what happens?
thanks again