CYA too high?

[AnnaK]

When I opened the pool this year my test strip read 0 CYA. I ran it for a while, vacuumed, brushed, tried to wait out theat blasted pollen that collects like yellow paste in the skimmer sock, got the water balanced, then tested at home with strips and reagents, and had two different pool stores test.

My strip CYA values read consistently <30. One pool store read 50, the other read 25. So I added 2 cups CYA over a two week period. Intermediate tests using the strips produced a reading of between 30 and 50. I was satisfied with that. But today I took a sample to Leslie's and their reagent test says 100!!! One of us is way off. His other results were close to mine: FC 1.5, pH 7.6, TA 110, CH 80, TDS 450 at Leslie's and FC 2, pH 7.6, TA 120, CH 0 here at home with stips and reagents (HydroTools).

I'm a little concerned about Leslie's high CYA reading, especially since it's so much higher than what the stips say. There's no way I can drain half the volume and refill from the well. I'd be at it for the rest of the season.

Is this a cause for concern? I read just recently that one of the Forum members has been running CYA at 80 without any apparent detrimental effects. Maybe I ought to have the other pool store test it. What do you think?

Oh, and as to the air bubble issue I had posted about earlier, tomorrow is the Big Detection Day. We've laid in a supply of Red Dog :)

[aylad]

You'll find that almost none of us on this forum will use test strips for anything but ballparks, because they are considered to be very unreliable. As for your CYA level, I would not trust any level that is obtained by any other way than with chemical reagent testing. If you do indeed have a CYA of 100, then you're going to have a hard time keeping algae out of the pool unless you run a chlorine level of around 10 (minimum) all summer. I do run my CYA at 80 - 90, but I am very consistent with keeping my chlorine levels up. I live in Louisiana and my pool is in full sun all day, so that's the only way I can keep chlorine in the pool. My suggestion is that you drain and refill, at least small amounts, as often as possible to bring the CYA down a bit. I wouldn't even leave mine at 100.

Janet

[AnnaK]

Hi Janet,

I use strips and reagents. The strips for a quick and dirty first thing in the morning, the reagents every other day, but the reagents I have do not test for CYA. The only way I can test for that is with either the strip or at the pool store.

I have to add water about twice a week, an inch or so each time, because the dogs drag out a lot. We've stimated we loose a gallon each time a dog leaves the pool. That comes to roughly (ruff-ly?) 50 gallons a day lost.

I also lose some volume when I backwash and rinse, so there's some refilling happening then, but I cannot possibly drain and refill to dilute the CYA level. My well won't take it. If the CYA is truly at 100 then I should be back to 50 by the end of the season :)

I will keep an eagle's eye on algae build-up and keep the Cl level up to compensate. Thanks for the heads up on that.