Arizona pool with High Calcium Hardness and Cyanuric Acid

[Nedaz]

Hi,
I live in Tucson AZ, and the water here is harder than the hubs of 7734.
Just tested with Taylor K 2006 Kit:
FC: 6ppm
pH: 7.4
TA: 160 ppm
Calcium hardness: 1250 ppm
CYA: 500
There's a Calcium crust at the tile/water interface that I've given up trying to remove with elbow grease. Trouble is it traps insect parts that make the pool surface less than attractive.

I now use clorox to sanitize from the CYA and your table I should use more but i'm off the chart. In the past ive used those 3 inch tablets, which i've learned are one of my sources of trouble.

My pool is a cement below ground level pool -- 28,000 gallons:
I have a cartridge filter (Hayward CX-1750)
A Haywood Super II pump, 1 1/2 hp which I run 8 hours each day.

What do I do to reduce the CH and CYA? Then how do i get rid of the calcium build up around the pool's edge?

Thanks

[kelemvor]

Unfortunately, the only effective way to reduce CYA is to replace some or all of your water. What is the CH of your fill water source? If it's much lower than 1250, you might get double benefit from doing at least a partial drain and refill.

With a CYA of 500, I'm not sure where you would even need to keep your chlorine level to maintain effective sanitation.

The calcium scaling can be softened by lowering the pH. You can buy gel "tile and liner" cleaner products which are acidic to localize the low ph and help you clean. Just be careful you don't reduce the overall pH in your water too much as you risk damaging pool surfaces much below 7.0

If your fill water is that hard, it might be worth your time to price out having fill water trucked in. Sorry I don't have any better advice to give you.

Since you've got tile by your waterline, you can use a razor blade to help scrape off the calcium. Home Depot/Lowes/Scotty's sell little handles for flat razor blades in the paint section of the store. I soften with tile/liner cleaner, and then scrape (with rubber gloves).

[PoolDoc]

Membership upgraded . . .

Wow. I don't recall seeing numbers that extreme, before, on a pool that was actually in operation.

OK.

1. Kelemvor is correct to point you to the need to test your fill water. In Tucson, your evaporation rate is going to be very high, which probably means you regularly have to top off the pool. You need to know what you are topping it off with.

2. There are two ways to lower CYA. Kelemvor has pointed you to the easy and straightforward one. If you can drain and refill for a reasonable price, that's the way to go. BUT, you'll need to be SURE to get test values on any water that's trucked in, BEFORE you buy it. It may not be worthwhile to truck in water that already has high calcium levels. The 2nd way involves allowing your pool to get slimy for a month or more . . . and then may require cleaning up ammonia. It's something to explore if water is really expensive for you.

3. It's possible to lower calcium by precipitating it, but it takes awhile, and you need to be able to manually vacuum the settled calcium carbonate off the bottom of the pool.


Bottom line: if you have affordable high quality water available, either from your tap or via truck, that is the preferable option. So, check that first.

[mas985]

There are also pool osmosis services which can remove CH/CYA from the water without having to refill. These usually cost more than a refill but if your water has high CH, it might be worth it.

https://www.google.com/search?num=50&newwindow=1&safe=off&rlz=1C1CHFX_enUS500US500&es_sm=122&q=Arizona+Reverse+osmosis+pool+filtering+service&oq=Arizona+Reverse+osmosis+pool+filtering+service&gs_l=serp.3...48407.53620.0.53967.16.16.0.0.0.0.12 3.1296.15j1.16.0....0...1c.1.27.serp..4.12.968.1iE Bxq1YdOA

[nefretrameses]

What exactly is the "hub of a 7734"? How hard is that?

[kelemvor]

It's just a euphemism.

[CarlD]

I don't even know how you could measure a CYA of more than 100 unless you diluted your pool water 4:1 with distilled water and STILL got a measure of 100ppm. Nor how you could get it so high.

[dubbedout]

I'm in Gilbert, AZ and have been battling high CYA since I bought this house 2 seasons ago. I just started working on my pool this season and found out my CYA is now around 30, when I started it was over 100. How did you get the CYA reading of 500? If it was from a local pool store, don't put too much value into their test results. Get yourself a Taylor K-2006 kit and test it yourself. As far as high CYA, I just dealt with it and let it lower itself naturally, I had to keep my chlorine levels around 10ppm for the whole season and in the winter I just let the pool filter run but added no chemicals (surprisingly it stays pretty clean, just a little cloudy). I immediately switched to bleach and/or liquid chlorine, this will stop adding CYA too your already high levels as well.

[PoolDoc]

Dubbed, you're responding to a post from last year. The OP hasn't been checking back in, so he's probably not paying any attention to this.