Which chlorine & why?

Chlorinating, maintaining the right chlorine levels,
chlorine problems. Dichlor, trichlor, cal hypo, bleach,
granules, chlorine pucks and chlorine sticks.

Which chlorine do you use in your pool?

Trichlor - granules, tabs, pucks
256
39%
Dichlor
64
10%
Cal Hypo
80
12%
Chlorinating liquid
145
22%
Bleach - supermarket style
112
17%
 
Total votes: 657
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BilliBob
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Which chlorine & why?

Postby BilliBob » Fri 27 Mar, 2009 04:06

I was wondering what folks are using to chlorinate their pools.

Please leave comments with reasons why you use the chlorine that you do.

I use trichlor granules and cal hypo. The trichlor for my stabilized chlorine and then cal hypo. Liquid chlorine always gets watered down where I am so it is an expensive alternative.

BilliBob


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chem geek
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Which chlorine & why?

Postby chem geek » Fri 27 Mar, 2009 12:30

What is the strength of the chlorinating liquid that you say is "watered down" and what is the price per gallon?

I use 12.5% chlorinating liquid from my local pool store which they sell for $3.80 per gallon. This is equivalent to $1.41 for a 3/4-gallon jug of 6% bleach (i.e. Clorox Regular or off-brand Ultra) so is a little more expensive than bleach in my area, but I return the bottles that they then reuse so this is better for the environment than recycling (or trash). My total chemical cost for my 16,000 gallon pool is around $15 per month, mostly for chlorine and a small amount (couple of cups) of acid per month. I have a pool cover so chlorine usage is low at 1 ppm FC per day.

When you compare prices for chlorine, you need to account for the fact that Trichlor requires the use of pH Up product (or Arm & Hammer Super Washing Soda). A cost comparison of chlorine sources is in this post . Bleach can be the least expensive while chlorinating liquid and Cal-Hypo are sometimes comprable, but Trichlor is even more expensive and Dichlor is much more expensive while lithium hypochlorite is out of this world.

Also, don't forget that Trichlor, Dichlor and Cal-Hypo add more than chlorine to the water. The chemical rules that are independent of concentration of product or size of pool are as follows:

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by 7 ppm.

With the stabilized chlorine source (Trichlor and Dichlor) the CYA level can build up rapidly unless you have a smaller pool with a sand filter you regularly backwash and have a short swim season with rains that overflow (dilute) the water. The higher CYA level requires a proportionately higher FC level to prevent algae growth unless you use a supplemental algaecide (PolyQuat 60 or a phosphate remover) at extra cost.

Richard
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Which chlorine & why?

Postby Me... » Fri 27 Mar, 2009 21:26

Liquid pool chlorine. In all my years I just can't see anything used so problem free for the most part. Even if it did at first appear to be slightly more expensive, the ease of use should more than make up for that.
Guest

Which chlorine & why?

Postby Guest » Thu 02 Apr, 2009 03:11

I use liquid or bleach because its easy and cheap.
Pooltech32
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Which chlorine & why?

Postby Pooltech32 » Sun 05 Apr, 2009 22:32

If I owned my own pool I would just use liquid chlorine, I service over 100 pools per week and most of them are on a weekly service so I have to use chlorine pucks, but they will raise your CYA levels which can create problems, they will also lower yower your TA over time so you will have to add alkalinity increaser as well
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Jeffm
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Which chlorine & why?

Postby Jeffm » Tue 28 Apr, 2009 21:14

I'm glad you posted this, as I've been wondering which one to use also.

So the liquid chlorine doesn't raise TA, CH or CYA at all?
chem geek
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Which chlorine & why?

Postby chem geek » Wed 29 Apr, 2009 01:16

Neither bleach nor chlorinating liquid (nor lithium hypochlorite, which is very expensive) raise either CYA or CH. They only add chlorine and extra salt. All chlorine adds salt since chlorine converts to chloride when it gets used up, but bleach and chlorinating liquid add twice as much salt. For every 10 ppm FC, all sources of chlorine end up with 8 ppm salt, but bleach and chlorinating liquid add an extra 8 ppm salt upon addition so result in 16 ppm salt. However, it takes quite a while to build up salt levels.

For example, even at 1 ppm FC per day chlorine usage, which is pretty low, Trichlor adds 18 ppm CYA and 24 ppm salt per month, Dichlor adds 27 ppm CYA and 24 ppm salt per month, and Cal-Hypo adds 21 ppm CH and 30 ppm salt per month. Bleach and chlorinating liquid add 48 ppm salt per month.

Liquid chlorine will not raise TA over time. However, pools that have evaporation and refill with water high in TA or CH wll have the TA or CH rise over time though adding acid along with normal carbon dioxide outgassing will prevent the TA from rising. So if one uses Trichlor (a very acidic source of chlorine) and has a higher TA level, then one can get to a roughly steady state of TA if there is evaporation and refill. Of course, the CYA will climb.

Richard
Bjorn
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Which chlorine & why?

Postby Bjorn » Thu 25 Jun, 2009 15:53

I use Cal-Hypo and Triclor and I´m aware of the the small consequences... :)
atlantispoolchemicals

Which chlorine & why?

Postby atlantispoolchemicals » Fri 18 Sep, 2009 17:41

Trichlor - granules, tabs, pucks are our most popular type of chlorine. Our current range is the far superior way to keep your pool clean and fresh. poolspachemicals uk
chem geek
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Which chlorine & why?

Postby chem geek » Sat 19 Sep, 2009 01:57

atlantispoolchemicals wrote:Trichlor - granules, tabs, pucks are our most popular type of chlorine. Our current range is the far superior way to keep your pool clean and fresh.

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm. This chemical fact is independent of concentration of product or of pool size. Even with a low daily chlorine usage of 1 ppm FC per day, continued use of Trichlor will add over 100 ppm CYA in 6 months if there is no water dilution. Do you tell your customers that?

As the CYA level climbs, the chlorine (at the same FC level) becomes less effective eventually leading to algae growth. Initially this may appear as an unusual chlorine demand but eventually will result in a green algae bloom. So if you use Trichlor and let the CYA climb and don't proportionately raise the FC level, then you need to use a supplemental algaecide or phosphate remover (at extra cost) and even that will only work up to some point of high CYA. Do you tell your customers that?

If you instead manage your CYA level by using mostly unstabilized chlorine such as chlorinating liquid or bleach (having some fixed CYA level already, such as 30-50 ppm), then you don't need to use an algaecide and don't need to shock regularly. You also won't need pH Up chemicals (at extra cost that actually make Trichlor more expensive that some other sources of chlorine) and with proper setting of TA levels you will only use a small amount of acid. This is, however, less convenient since you need to add chlorine every day or two unless you have a pool cover in which case you can add it around twice a week. Do you tell your customers that?

In my own 16,000 gallon pool shown here , I only use 12.5% chlorinating liquid from my pool store plus a couple of cups of acid every month or two. I have a low chlorine usage of around 1 ppm FC per day because I have an opaque electric safety cover, though the pool is used and open for 1-2 hours every day (more on weekends). This costs me around $17 per month -- that's it (for chemicals -- chlorine prices have recently risen; pump electricity costs are much higher as I have solar that requires higher flow rates).

Richard

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