Very High CYA Levels

[RobHar]

30K, IG Fiberglass w/DE Filter
FC-0, TC-0, pH-7.0, TA-30,CH-230, CYA-300+
These were the results from the local pool store. They say my best course of action at this point is to drain half the water and start over. Water in CA is very expensive. Is there a better way to get the chemicals in balance?

 

[Bama Rambler]

Even given that we don't trust pool store numbers, I'm afraid that you're going to have to replace a lot more than half of your water.

Is that CA California or Canada?

If it's california, Reverse Osmosis might be available to you. It's probably going to be as expensive as replacing the water though.

 

[Richard320]

Welcome!

While that number is possible, I wouldn't trust it. Pool store tests are notoriously unreliable. And if you live in CA, I wouldn't trust that CH reading, either, since everywhere I've lived, the water is really hard. I would expect that number to be far higher.

There is no easy way to lower CYA short of draining, unless you live close to Escondido, where there is a reverse osmosis outfit that can filter everything out. However, the pool has to be clear, so....

What does your water look like?

And have you read anything in Pool School yet?

 

[JohnN]

The first step is to get the recommended test kit. Assuming CA means California, you would be best off ordering from poolsupplyworld.com. If that number is accurate, and your CYA really is 300, that would mean you have to drain 83% of your water. If RO is available by you, from what I remember it costs around $400.

 

[Donldson]

Welcome to TFP!

Unfortunately I don't have any better news than the previous replies. I don't trust pool store results, but with CYA tests they are more likely to read too low than too high. You would have to test yourself to be sure but if your CYA is well over 300 you will have to drain some 25k gallons of water or do a reverse osmosis treatment. At this point you would have to keep your chlorine level above 23 for it to have any useful effect.

So did the pool store tell you why your CYA level is that high? Chlorine tablets (made from trichlor) and some "shock" powders (made from dichlor) add CYA along with the chlorine. Am I correct that you use tablets to chlorinate your pool?

 

[RobHar]

Thanks, I'll do some more research before draining.

 

[RobHar]

Using granular chlorine.

 

[Bama Rambler]

Granular cholorine comes in three formulas. Dichlor, Cal-hypo and Trichlor. It's obvious from your CH reading that you're not using Cal-hypo. It's probably Dichlor and that adds 9 ppm of CYA for every 10 ppm of FC you add. That owuld be why your CYA is so high.