How Do You Lower CYA?

[waterbear]

It can take a very long time for the CYA to go down on it's own, expecially if you have a cartridge filter. CYA will only go down by dilution under normal circumstances. This means refilling from splashout, backwashing a filter, or draining and refilling. Evaporation will merely concentrate it and it will dilute to where it was before when the evaporated water is replaced. Using bleach or any other non stabilized chlorine will not make it go down. However, using trichlor or dichlor will make it rise since with every use of these products you are adding more CYA!

BTW, most powdered shock is Cal Hypo (calcium hypochlorite) and is non stabilized chlorine. Dichlor is ususally only recommended for shocking spas which get drained and refilled every 3 months. It is ususally used in poos for normal sanitation.

[gordyjamz]

Last year I was running with cya of 60-70, but when opening this year I noticed it was down to 30. This was before I refilled back to normal level, at which point it was down to under 20. I had to actually raise it. I think it goes away when the water sits over the winter. So it may be less hassle to just run with higher cl level this year and see where you stand next spring and adjust accordingly then.

[crackerjack]

In The Swim has cyanuric acid remover that is capable of removing 30-50 ppm of cyanuric acid in 10,000 gallons of water.
At $50 a gallon, not sure if it would be worth it though.

[Watermom]

This has been discussed on the forum before and it is not recommended that this product be used.

[let_her_flicker]

Do not add any CYA remover. It will only make matters worse.

Waterbear is right about the evaporation and I should not have mentioned that. I also should have worded my response clearer by stating that by using bleach you are not adding anymore CYA. I was including the fact that you will have splash out and rainfall which dilutes concentration in your pool.

Watch out for the powder shock. Some are 4 in 1 shocks that have stuff in it your pool doesn't need. You can shock just as easily with liquid bleach.

Patience is the key with this issue. If you don't like your CYA level when you open next year, you can always drain a little more water away.

Another item that will lower your CYA is when you vacuum your pool, do it to waste. Then you are removing a small amount of CYA and when pool water is replenished either by hose or by rainfall it will not have any stabilizer in it.



Sorry for the confusion. Good Luck

[waterbear]

In The Swim has cyanuric acid remover that is capable of removing 30-50 ppm of cyanuric acid in 10,000 gallons of water.
At $50 a gallon, not sure if it would be worth it though.

It removes the cya by causing a precipitaton reaction that turns the water very milky. It is melamine, exaxtly the same as the reagent used to test for CYA in our test kits. You know what that tester tube looks like with high CYA levels...imagine your pool looking like that for a week! Also, from what feedback I have heard about CYA reducers/removers...they lower the CYA more in the range of 20 ppm per 10000 gal. Do the math. A water change is cheaper (and will probably take less time!)

[aquarium]

A water change is cheaper (and will probably take less time!)

I'm sorta surprised that a water change isn't recommended here more often. I see a lot of people throwing a lot of chemicals and/or bleach at problems, when a simple water change would solve things right away. Gets you back to a known baseline.

TW

[cheshamjim]

I checked the label of my old (never-to-be-used-again) sanitizer, a hugely expensive product from BioGuard called Smart Shock. It is 63% sodium dichloro-s-triazinetrione. Using this stuff for 4 plus years, along with "Smart Sticks" (slow desolve tablets) is probably the source of my CYA problem.

Water drain and replacement may be an easy solution for many pools, but my vinyl lined pool doesn't like to be drained. I drained about a third of my water earlier this year and ground water caused the sides to billow inward. Thank goodness everything went back into place when refilled. But my draining problem is why I was so interested in the idea of a membrane (tarp) to aid the process. I think I'll post something on the Pool Construction and Repair forum on the subject.

Thanks everyone for your suggestions. I am always amazed at how useful this forum is.

-Jim

[let_her_flicker]

I'm sorta surprised that a water change isn't recommended here more often. I see a lot of people throwing a lot of chemicals and/or bleach at problems, when a simple water change would solve things right away. Gets you back to a known baseline.

TW

Some people live in places where you just cannot dump 5 or 10 thousand gallons of water into their yard. Drainage can be an issue where it goes into a neighbors yard, etc. Without knowing the particulars of a situation it is easier to add those "low cost" grocery store chemicals to solve the problem.

[aquarium]

Ah, okay. I guess we're 'lucky' to live in a drought area.

That's a special challenge, the caving walls, that vinyl pools present. It would seem to me that that makes the trichlor pucks completely unsuitable in that case. Wonder how many pool companies tell people that.

TW