Chlorine option for commercial size pool

[Zadd]

Taking care of a new commercial pool. Began with SLAM & passed the OCLT. 40ppm CYA. 115 total volume. pH stable at 7.8. CA around 175ppm.

Got very tired of transporting 21 gallons of liquid each week as it was requiring three per day. So I opted for Hypo Chloride at $2 per 1ppm raise in Cl. This cut cost from liquid by about $4.50 per day. Now I only transport 150lbs of Hypo Chloride to this pool per month, saving some effort.

If I continue to use Hypo Chloride and watch the CA levels (keeping below 300ppm) could I potentially do this all summer? Does Hypo Chlorine burn off any faster than liquid? Any issues I’m not seeing with this product?

 

[jblizzle]

Once it is in the water ... the chlorine source does not matter. It will behave the same as far as losses to the sun (that is function of your CYA level).

In a 115,000 gallon pool, 150 pounds of cal-hypo will be adding up to 80ppm of CH. So in 1.5 months you will exceed that arbitrary 300ppm that you stated.

 

[Zadd]

I see your point. I’d have to backwash and fill frequently to keep under my CA limit. I set 300ppm limit because of my goal Saturation index and I feel as if the other variables are stable.

 

[Stargate_to_earth]

sounds like you need to stick to higher concentrations of Liquid Cl.

Also there are services that will deliver higher concentrations in larger volumes...

Or if the budget is quite high you can look into Lithium based salts...

 

[Zadd]

I’m not opposed to getting 55gallon of 12.5% delivered like at another pool I run but lugging those are a real pain in this application.

I’ve never heard of the lithium based salt. I may research that.

 

[jblizzle]

Your budget will not like the lithium.

 

[CJadamec]

At almost 100 gallons a month of usage I'm sure you could get somebody to deliver 55gal drums to the pool then just setup a stenner injection system so all you have to do is take the cap off the barrel and move the stenner suction hose from the empty barrel to the full barrel.

 

[cfherrman]

At almost 100 gallons a month of usage I'm sure you could get somebody to deliver 55gal drums to the pool then just setup a stenner injection system so all you have to do is take the cap off the barrel and move the stenner suction hose from the empty barrel to the full barrel.

+1

Or you can spend gobs of money for clorine gas injection

Or spend some more money for 6 40k swg

 

[Donldson]

Lithium is expensive and getting harder and harder to find. Apparently all of us walking around with several lithium batteries in our pockets has shifted the demand for lithium away from the pool industry. $10/lb is not unusual. It also has less chlorine per pound. It would take 8 lbs a day to keep up with your described usage. So that would take your cost from $6-10/day to $80/day.

Probably not an option...

Be sure you are factoring in the cost of water replacement in switching to cal-hypo. As Jason pointed out, you will raise your CH by 80/mo at the current rate. Using Houston's fairly soft water with only 17 CH as a guide you would need to replace 32,000 gallons of water every single months. Your CYA will also need replaced as you drop it. So if 32,000 gallons of water and 15 lbs of CYA costs more than $135 then you are losing money by switching to Cal-Hypo.

 

[Zadd]

So here is an interesting add on to the story...I took my typical 5 year re-up of CPO training class. Our instructor was very big on Cal-hypo as a source for chlorine. When I asked about his usage getting above 300ppm he told me that CA is a metal and has coagulated properties above 400ppm. I asked about scaling and he did say that pH can never go above 8.0 or scaling would occur. Any thoughts on this line of thinking???

 

[duraleigh]

Any thoughts on this line of thinking???

Of course, the instructor is incorrect. I am not sure what you mean by "coagulated" but I assume he was referring to a point where the pool water is saturated with Calcium and will precipitate into a solid. Even if it were true (it's not) that would be a bad thing..........it is important to keep CH in soluble form and not let it precipitate.

Follow the guidelines set forth here at TFP and you won't go wrong. Please read "The "ABC's of Pool Water Chemistry" up in Pool School. It should give you a better understanding of CH and why it is important you are aware of it.


No EASY solution to your original chlorinating concerns. Cal Hypo will work but it has some side effects that are troublesome. Liquid chlorine is by far the best but dealing with the bulk is troublesome as well.

Since you are apparently allowed to use CYA, bring your CYA up to 60-70 and your liquid chlorine consumption will reduce.

EDIT: I forgot about your significant rainfall in Houston......about 50 inches. As long as you capture this rainfall and your fill water stays low in CH, You can probably manage Calcium a little easier than I was originally thinking.