Choosing Among Leslie's Products

Chlorinating, maintaining the right chlorine levels,
chlorine problems. Dichlor, trichlor, cal hypo, bleach,
granules, chlorine pucks and chlorine sticks.
Pool Newbie
Pool Newbie
Posts: 1
Joined: Sun 09 Sep, 2012 19:53
My Pool: in-ground vinyl, apprx 16K gallons.
Location: Texas

Choosing Among Leslie's Products

Postby TX_Pool_ » Sun 09 Sep, 2012 20:16

Okay. I live in South Texas. I use Leslie's products in my in-ground vinyl pool. i have always used Chlorbrite, Chlorine tabs and Fresh n Clear.

I recently bought some Power Powder, and have never used it before, and not sure I want to start.

Any pros, cons? It seems chlorine tabs, chlor-brite, and fresh n clear are an unbeatable combination.

Any thoughts?

chem geek
Pool Industry Leader
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Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Choosing Among Leslie's Products

Postby chem geek » Mon 10 Sep, 2012 12:22

Chlorbrite is Dichlor.
Chlorine tabs are Trichlor.
Fresh 'n Clear is non-chlorine shock (potassium monopersulfate aka MPS)
Power Powder is Cal-Hypo.

The following are chemical facts independent of concentration of product and of pool size:

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 at least 7 ppm.

So continued use of stabilized chlorine (Trichlor or Dichlor) products usually results in increasing CYA levels over time. Higher CYA lowers chlorine effectiveness unless the FC level is raised proportionately to keep the FC/CYA ratio constant. Depending on the amount of algae nutrients (phosphates, nitrates) in the pool, this can lead to algae growth towards the end of the season when the CYA has built up. CYA is only significantly reduced by water dilution though some pools get a bacterial breakdown of CYA over the winter when let go so open to low or zero CYA (though can also open to ammonia as a result which has a huge chlorine demand). If one has a small pool with a short swim season and backwashes a sand filter weekly, then one can have enough water dilution to keep CYA in check. However, without such dilution, a 2 ppm FC per day chlorine usage using Trichlor would increase CYA by 36 ppm per month.

If you maintain your pool with a minimum FC of at least 7.5% of the CYA level, then you can prevent algae growth with chlorine alone regardless of algae nutrient level. This lets you avoid use of any algaecide, phosphate remover, clarifier, flocculant, enzyme or any regular shocking. It is more frequent maintenance since one must dose the pool every day or two with chlorinating liquid or bleach. So while Trichlor tabs/pucks are certainly convenient due to their slow continuous dosing, they have a downside. One can compensate for this by using supplemental products at extra cost so it's a cost/convenience tradeoff.

As for non-chlorine shock, it is usually not necessary in an outdoor residential pool exposed to sunlight. It's very expensive and doesn't do anything significant that chlorine and sunlight don't do together.

Read the Pool School to learn more.

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