Replacing water to get rid of CYA

[xcapecod83]

I just discovered the whole CYA issue. I know I need to replace water to get rid of CYA (it's 150). I was surprised to learn that although I have a pool pump, there's no way to use it to drain water. I need to rent a pump at the cost of about $50/day. I was also told to drain only about half of the water at any time in case there's water below the pool that could cause the empty pool to rise (unlikely where I live in Southern California -- but I'll play it safe). Therefore I may need to keep the pump for 2 or 3 days.

Does anyone know if i can replace water effectively by turning on my filler line and letting water drain out the overflow. Since the water comes in on the surface and the overflow is also on the surface it seems like I might just be losing the new water. Maybe running the filter at the same time would circulate the water? I'd appreciate any information anyone has.

The pool is 17,000 gallons and goes from 3.5' to 8'.

Thanks,

Larry

[duraleigh]

Hi, Larry,

Can you backwash and dump your water that way? How about vacuum to waste?

If "no" on the above, can get the other end of a hose lower than the pool surface?.....so you can siphon.

PS - you got good advice on only draining half....better to be on the safe side

[tmmort]

I was exactly in your situation about a month ago (CYA 150+, also high CH). So I rented a sump pump from a pool store and drained it until the entire shallow end was dry - I estimate 2/3 of the water out.

It took about 12 hours and my pool is a little larger than yours (20K gallons). Took about the same time to refill using garden hoses.

At the time, I was very concerned about this, but turned out just fine. Water has never been better; it's great to have everything back in balance!

Something to check: here in No. Cal. you can't drain the pool water down the street and into the storm drain; but, you can drain it to the sewer. Look for a sewer clean out and direct the flow there.

[xcapecod83]

Hi, Larry,

Can you backwash and dump your water that way? How about vacuum to waste?

I don't think I can backwash -- I thought that was for DE filters and I have the cartridge variety. I also can't get a hose lower than pool, so I'm stuck with one of the other 2 methods.

[Poconos]

Larry,
Welcome to the forum.
On the draining...should be no need to rent a pump. Use the vacuum hose in the skimmer. Should let you drain well below skimmer level. Or, you can get a cheap Flotec sump type pump at Home Depot for $70 or so. Handy thing to have anyhow.
But...consider this....since you are looking for a major water change, some people have used a big plastic sheet to cover the pool as a separation membrane. If the width of the sheeting isn't enough you can tape sheets together using multiple layers of duct tape. Doesn't hold up long but will be good enough for the couple days it needs to hold. Cover the pool and start adding new water onto the top while you're draining out the bottom. 100% replacement. You never get a 100% replacement if the liquids mix. Another advantage is the water level never drops so you don't have to worry about floating the pool or liner. It does work. Saw a local with a new pool installation doing this last year.
Al

[xcapecod83]

I was exactly in your situation about a month ago (CYA 150+, also high CH). So I rented a sump pump from a pool store and drained it until the entire shallow end was dry - I estimate 2/3 of the water out.

What was your CYA after the drain? I was anticipating I'd need more than one partial drain, but perhaps not. I did check the regs for where I live.

[xcapecod83]

Larry,
Welcome to the forum.
On the draining...should be no need to rent a pump. Use the vacuum hose in the skimmer. Should let you drain well below skimmer level. Or, you can get a cheap Flotec sump type pump at Home Depot for $70 or so. Handy thing to have anyhow.

Thanks, Al. A couple of questions. I'm not sure what you mean using the vacuum hose in the skimmer. Also, for the plastic sheets do they just float on the surface? I have one of those kidney shaped pools.

[Poconos]

I'm thinking of the vacuum hose setup that hooks to the skimmer. Should be able to hook it as you would for vacuuming but set the valve to waste and leave the hose in the deep end of the pool.

The plastic sheet will float. Just start filling on top and let it sink as you suck out the bottom. Shape of the pool shouldn't matter as long as the sheets cover the pool with enough overlap to account for dropping down as you fill.
Hope this answers your questions...if not...ask again.
Al

[tmmort]

What was your CYA after the drain? I was anticipating I'd need more than one partial drain, but perhaps not. I did check the regs for where I live.

One pool store said 30, another said 50. When I receive Ben's kit I'll know for sure

[MarkC]

I like Poconos plastic sheet method.