Salt Water test kit

[aztony]

Hi all. I was wondering if the test for SW is supposed to have these white flakes? The SWG is reading lower than the test kit. It's reading 2800 and the kit is giving me 3000 - 3200. Does the test kit go bad or lose it's accuracy? Or is the SWG giving a false reading? I've recently cleaned the SWG and cartridge filters a few days ago.

 

[ajw22]

The salt test reagents are very stable. Your test results are likely correct.

Hayward Aquarite cells calculate lower salt as they age.

Hayward Aquarite SWG - Further Reading

www.troublefreepool.com

 

[TinFoilHat]

Your vial looks a little crusty there. Try cleaning it with alcohol.

 

[DrewLG]

Try cleaning it with alcohol.

Alcohol is great for the black stains left by the chlorine-test powder, but it doesn't work on the salt-test residue.

Use ammonia instead. Original-formula Windex is perfect for the job.

 

[Lake Placid]

Hayward indicates a margin of error within of 500 ppm of an independent test kit is acceptable. Your cell is reporting within 200-400 ppm of your test. Well within the margin of error that is considered normal.

 

[aztony]

Thanks for all the responses. Good to hear the cell is still good. I'm shocked at the price of a new T15. The last time I purchased one back in 2015 it cost $350. Now I see prices are over $1k.

One question on the SW test, the white flakes are normal? I do rinse out all the test tubes before and after testing. Can vinegar be used to clean the tubes?

 

[DrewLG]

One question on the SW test, the white flakes are normal?

Yes.

I do rinse out all the test tubes before and after testing. Can vinegar be used to clean the tubes?

It won't work as well as ammonia. An explanation of the relevant chemistry, from @AUSpool and @JamesW, is here: Thread 'Salinity test residue' https://www.troublefreepool.com/threads/salinity-test-residue.300573/

 

[JamesW]

Salinity test residue

What is the white residue left in the test vial after the salinity test, and more importantly, what dissolves it? It doesn't seem to be soluble in water or alcohol, and I'm not sure that my current mechanical cleaning method is removing all of it.

www.troublefreepool.com

 

[PoolStored]

Does the test kit go bad or lose it's accuracy?

Yes. R-0718 is one of the reagents more sensitive to degradation. I have had a test kit go bad before the expiration date on the test bottles. This was stored in a cool dark place. When the test goes bad, your results will be higher than expected. The R-0718 should be colorless. It should be replaced annually. ( Recognizing A Compromised Reagent )

Given the condition of your box, I'd consider replacing the reagents.

 

[aztony]

An off topic question: How often should the pool water be changed? I've heard two different opinions. Every few years and not at all as long as it is chemically balanced it's not necessary. It's been years since I've changed the pool water.

 

[proavia]

Your biggest issue will probably be CH rising.
Do you have a whole house water softener that can be plumbed to your autofill?

What the CH, TA and pH of your fill water?

No water softener plumbed to the autofill and high CH fill water, you will probably need to drain every 2-3years.
With a properly functioning water softener, youcan go many years before a drain might be needed.

 

[aztony]

I do have a whole house water softener but it isn't plumbed to the outside spigots or the autofill. I have never tested the fill water. Would that be just the water out of the outside spigot?

 

[PoolStored]

Would that be just the water out of the outside spigot?

Whatever water source is used to replace water. Spigot, autofill, whatever the source.

 

[proavia]

Try the spigot in the front yard near where your water shutoff is - or from near where the autofill is connected.
We need to know the CH, TA and pH of the untreated water.

Serious try to plumb soft water to the autofill to all but eliminate CH rise after the initial fill using hard water.