High CYA

[CypressTx]

1st, I have a stenner pump, I just haven’t installed it yet.
In the meantime I’m paying a company to maintain my pool :/. Ya, it’s a waste.
So today he let me know my CYA is too high and has been for awhile and he’s not been able to bring it down so he’s recommending not only draining it but draining it 100%! He said CYA concentrates in the deep end and if we don’t drain it all we won’t know how much CYA level we’ve brought it down to and it’s a lot better to just start fresh. He said he has a pump that can drain it in 30 min so we won’t have to worry about it lifting (were in Houston TX btw). Total cost $300 to fully drain, pressure wash, fill, balance, and clean 4 cartridges. Plus additional water bill to refill (we have around 15k gal or so).
So aside from the fact I need to finally get my stenner installed (I am not handy so I’ve been procrastinating) is what he’s recommending necessary?

 

[mknauss]

OK.

CYA does not 'concentrate' anywhere. It is in all the water.

No matter how long you have an empty shell in the ground if you have shallow ground water and / or saturation from rain the pool shell can lift out of the ground.

What is your CYA? If you plan to manage your own pool you need your own proper test kit. Do you have one?

The safest way is to exchange your water. I have a process for that, but, it is something a 'pool guy' will not do as it will take a couple days with your size pool.

Until you know all your water chemistry values, you do not know what you need to .

 

[CypressTx]

Yes I have a good Taylor kit. my cya is 80. How do you exchange the water?

 

[mknauss]

You can exchange some water without draining.

If you place a low volume sub pump in the deep end and pull water from there while adding water in the shallow end (through a skimmer or into a bucket on a step so you lessen the water disturbance) you can do a fairly efficient exchange. That is assuming the water you are filling with is the same temperature or warmer than your pool water. If your fill water is much cooler than your pool water, then switch it. Add the water to the deep end (hose on bottom) and pull water from the top step.

The location of the pump and fill hose may change if you have salt water, high calcium, etc.
In my pool, with saltwater and high calcium when I drain, I put the pump in the deep end and hose in shallow end. The water in the pool weighs more per unit volume than the fill water from the hose.

Be sure to balance the water out and water in so the pool level stays the same. Also be sure your pool pump is disabled during this process. Once started do not stop until you have exchanged the amount of water you wish.

 

[CypressTx]

actually I just took my own reading and it’s over 100. My Taylor doesn’t go over 100.

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Thanks the temps are about the same. If it’s over 100ppm how long should I do this for before stopping and testing again?

You can exchange some water without draining.

If you place a low volume sub pump in the deep end and pull water from there while adding water in the shallow end (through a skimmer or into a bucket on a step so you lessen the water disturbance) you can do a fairly efficient exchange. That is assuming the water you are filling with is the same temperature or warmer than your pool water. If your fill water is much cooler than your pool water, then switch it. Add the water to the deep end (hose on bottom) and pull water from the top step.

The location of the pump and fill hose may change if you have salt water, high calcium, etc.
In my pool, with saltwater and high calcium when I drain, I put the pump in the deep end and hose in shallow end. The water in the pool weighs more per unit volume than the fill water from the hose.

Be sure to balance the water out and water in so the pool level stays the same. Also be sure your pool pump is disabled during this process. Once started do not stop until you have exchanged the amount of water you wish.

 

[ajw22]

actually I just took my own reading and it’s over 100. My Taylor doesn’t go over 100.

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Thanks the temps are about the same. If it’s over 100ppm how long should I do this for before stopping and testing again?

Follow step 8 in Pool School - CYA and do the 50% dilution test.

 

[mknauss]

Do Step 8 in Pool School - CYA. That will let you test your CYA above 100.

You cannot stop and test the water. The process relies on segregation by weight and/or temperature. So once you decide that you have exchanged enough (based on time and volume) you then start your pool pump, mix the water for a few hours, and then test.

 

[CypressTx]

Wow I ended up at 140. How long do I do the replacement? My pump says up to 2400gph. Also it’s supposed to rain a lot today and tomorrow.

Follow step 8 in Pool School - CYA and do the 50% dilution test.

 

[mknauss]

What pump are you using? Remember you must use a hose to run the water your pumping out to either your sewer clean out or the street. Also, you can only pull water out at the same rate you can add it.

I use a 1/3 hp sump pump. I get about 7 gpm (420 gph) using a 50' garden hose to take my waste water to the sewer cleanout.

When you are prepared to start, you need to test your actual pump rate using a 5 gallon bucket. Time that and then determine the actual gpm your pump puts out.

 

[CypressTx]

It’s a 1/3 submersible pump.

What pump are you using? Remember you must use a hose to run the water your pumping out to either your sewer clean out or the street. Also, you can only pull water out at the same rate you can add it.

I use a 1/3 hp sump pump. I get about 7 gpm (420 gph) using a 50' garden hose to take my waste water to the sewer cleanout.

When you are prepared to start, you need to test your actual pump rate using a 5 gallon bucket. Time that and then determine the actual gpm your pump puts out.

 

[mknauss]

OK -- so I suspect your actual flow rate will be near what I experience.

At that rate (7 gpm), you will want to run for at least 20 hours. I would suggest to go for 24 hours. That way you are assured of reducing your CYA to below 50 ppm even if you get some mixing during the process.

 

[Yorker]

Great information Marty - I'm bookmarking this for the future!

 

[CypressTx]

Why such a big discrepancy on the pumps “up to” 2400gph rate vs reality out of curiosity?

OK -- so I suspect your actual flow rate will be near what I experience.

At that rate (7 gpm), you will want to run for at least 20 hours. I would suggest to go for 24 hours. That way you are assured of reducing your CYA to below 50 ppm even if you get some mixing during the process.

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Also what if it starts raining real hard like it’s going to?

OK -- so I suspect your actual flow rate will be near what I experience.

At that rate (7 gpm), you will want to run for at least 20 hours. I would suggest to go for 24 hours. That way you are assured of reducing your CYA to below 50 ppm even if you get some mixing during the process.

 

[mknauss]

The rated rate is at 0 TDH. You add the hose and any elevation change and your rate goes down.

If the rain is not enough to overflow the pool it should not mak a difference. I have never had to deal with rain that could do that here in the desert.

 

[CypressTx]

We’re supposed to get about 1.3” in the next 24 hours.

The rated rate is at 0 TDH. You add the hose and any elevation change and your rate goes down.

If the rain is not enough to overflow the pool it should not mak a difference. I have never had to deal with rain that could do that here in the desert.

 

[mknauss]

That’s pretty minimal. If necessary you could reduce the amount you are adding via the fill hose if the rain maintains the level of the water.

 

[CypressTx]

Argh. Drained while filling for 20 hours, ran the pumps for a couple hours after, and I’m still getting readings of around 100 . Go another 24?

 

[mknauss]

Sounds like you are not getting very good segragation. I suspect your fill water is cooler than your pool water. A few degrees makes a difference.

Up to you. You have to see if the conditions are OK to just drain about 50% and refill. That assures you of replacing the water.

 

[CypressTx]

Thanks again. I just rented a 55gpm sump pump. Hopefully my drains can keep up.

Sounds like you are not getting very good segragation. I suspect your fill water is cooler than your pool water. A few degrees makes a difference.

Up to you. You have to see if the conditions are OK to just drain about 50% and refill. That assures you of replacing the water.

 

[CypressTx]

I just realized my water softener wasn’t bypassed yesterday when I was doing the exchange. I just bypassed it after draining around 30-40%. Any concerns with that?

Sounds like you are not getting very good segragation. I suspect your fill water is cooler than your pool water. A few degrees makes a difference.

Up to you. You have to see if the conditions are OK to just drain about 50% and refill. That assures you of replacing the water.