Sustain system and testing combined chlorine

[mikefamig]

I have a question for those familiar with "Sustain" pool sanitizing system.

I have read that an OTO test for combined chlorine will give a false high reading when using the Sustain system. It said that the summer shield product somehow interefered with the test. The article went on to say that a DPD test will read combined chlorine accurately with Sustain.

Does anyone here know for certain that a DPD test is accurate in measuring both free and combined chlorine when using the Susdtain summer shield product?

Mike.

 

[mikefamig]

this is from the Sustain site:

Why can't I use an OTO test kit when using Sustain?
OTO does not clearly show the difference between free and combined chlorine and therefore should not be used when the pool is treated with the Sustain Pool Care System. Sustain Summer Shield Chlorine Extender holds a backup reserve of chlorine that tests as combined chlorine. To avoid confusion, use DPD or 3-Way Test Strips to measure FAC without interference.

Ask Joe Pool > Questions

 

[cfherrman]

Sounds like a snake oil product, more on that later.

We use fas-dpd testing from a tf100 or Taylor 2006c to measure fc and cc in .2 or .5 resolution up to 50 ppm.

Cya is what sheilds clorine from the sun and holds it in reserve, it shows up on a cya test and not cc, anything that says it does that and shows up as cc is going to be bad for your pool.

Read up on pool school here, you only need a test kit, bleach, and acid.

 

[mikefamig]

I understand this, I've been caring for my pool that way for nearly 20 years. We started the Sustain based on recommendations from neighbors. It's called the school of hard knocks.

 

[Flying Tivo]

Sustain Energizer Tabs contentsescription
[FONT=&quot]Axiall Sustain(R) Shield Energizer, Product Type: Sanitizers, Container Size: 10 lb, Pail Container, Various, Form: Solid, Odor: Slight Chlorine, pH Rating: Alkaline, Relative Density: 1.07 - 1.4 (67 - 71 lb/cu-ft), Chemical Composition: 65 - 76% CALCIUM HYPOCHLORITE, 10 - 30% SODIUM CHLORIDE, 1 - 3% CALCIUM CARBONATE, 1 - 3% CALCIUM DIHYDROXIDE, 0 - 3% CALCIUM CHLORATE, Boiling Point: 338 - 356 deg F, Solubility: Soluble in Cold Water


[/FONT]

 

[mikefamig]

Sustain Energizer Tabs contentsescription
Axiall Sustain(R) Shield Energizer, Product Type: Sanitizers, Container Size: 10 lb, Pail Container, Various, Form: Solid, Odor: Slight Chlorine, pH Rating: Alkaline, Relative Density: 1.07 - 1.4 (67 - 71 lb/cu-ft), Chemical Composition: 65 - 76% CALCIUM HYPOCHLORITE, 10 - 30% SODIUM CHLORIDE, 1 - 3% CALCIUM CARBONATE, 1 - 3% CALCIUM DIHYDROXIDE, 0 - 3% CALCIUM CHLORATE, Boiling Point: 338 - 356 deg F, Solubility: Soluble in Cold Water

Thank you but I'm not a chemist and only understand a few of those items.

Mike.

 

[Flying Tivo]

Bleach, Salt and Calcium!

Felipe

 

[cfherrman]

It's mostly cal hypo and salt, pass