What to do while waiting to drain pool

ChapmanTrav

Member
May 16, 2019
8
Central California
First post here. Like others here I used a pool service after building my pool a few years ago. In order to save money I started doing maintenance myself. When spring came I was not on top of my chlorine level like I should have been and now I have a little green algae mostly in the corner of the seats.
I set out to the internet and of course found TFP. I received my TF-100 kit yesterday and had my first test and here are the results:
FC 2.5
CC 0.5
TC 3
pH 7.8
Ca 1300!
TA 180
CYA > 100, I will do dilution test tonight to nail this down.
I know I am going to need to dump some of the water but in my town it requires a permit which may take a little bit of time. Anything I should work on in the mean time other than getting the FC levels up? I'd like the kids to be able to swim still.
Many thanks!
TC
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,404
Laughlin, NV
To safely swim the FC needs to be above the minimum based on your CYA. The minimum is based on 5% of the CYA level. And you must be able to clearly see the bottom of the deep end.

Otherwise, I wouldn't do anything to the water until you drain.

One caveat to draining, your plaster should not be left dry in the sun as it can crack and fail. You can exchange your water if you like.
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.
 
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Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
805
Rancho Cucamonga, CA
Your CH is registering real high, but not unrealistic. Just confirm you used a 10 ml sample and multiplied by 25 (52 drops). If you used a 25 ml sample your CH would be 520. It's a common error, so I thought I would mention it.

You should test the CH, pH, and TA or your fill water. You'll need the CH when it comes time to calculate the amount to drain.

Good luck on the drain/refill.
 

ChapmanTrav

Member
May 16, 2019
8
Central California
To safely swim the FC needs to be above the minimum based on your CYA. The minimum is based on 5% of the CYA level. And you must be able to clearly see the bottom of the deep end.

Otherwise, I wouldn't do anything to the water until you drain.

One caveat to draining, your plaster should not be left dry in the sun as it can crack and fail. You can exchange your water if you like.
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.
How do you know what perecentage of the pool has been drained if you are filling it at the same time? Keep testing CYA levels as you are drain/fillling?
 

ChapmanTrav

Member
May 16, 2019
8
Central California
Your CH is registering real high, but not unrealistic. Just confirm you used a 10 ml sample and multiplied by 25 (52 drops). If you used a 25 ml sample your CH would be 520. It's a common error, so I thought I would mention it.

You should test the CH, pH, and TA or your fill water. You'll need the CH when it comes time to calculate the amount to drain.

Good luck on the drain/refill.
Yes it was 50 drops in 10 mL. The hard water is brutal. Lots of calcium scale on my hot tub spillover!
 

Oly

Gold Supporter
Jun 28, 2017
1,169
Fresno, CA
Not sure where you are in the Valley but we are having a cool spell now and it would be a good time to drain some water. Where we live we can apply with the city on-line and they do ask about CYA levels. Home Depot rents pumps and hoses, we drained our pool in 6 hours, cleaned and refilled overnight. Start fresh and follow the TFP method you will not regret it.
 

ChapmanTrav

Member
May 16, 2019
8
Central California
Not sure where you are in the Valley but we are having a cool spell now and it would be a good time to drain some water. Where we live we can apply with the city on-line and they do ask about CYA levels. Home Depot rents pumps and hoses, we drained our pool in 6 hours, cleaned and refilled overnight. Start fresh and follow the TFP method you will not regret it.
I’m in Visalia. I got a permit for the 25th just have to make sure my chlorine level is undetectable by then. Can’t wait to try the TFP method. It’s like science class all over again
 

Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
805
Rancho Cucamonga, CA
Remember to test the CH of your fill water. Being so high, your drain amount will likely be based on CH as opposed to CYA. On the Pool Math page, you can enter you current, goal, and fill CH levels to determine the drain percentage. You will likely need nearly a full drain/refill.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,404
Laughlin, NV
How do you know what perecentage of the pool has been drained if you are filling it at the same time? Keep testing CYA levels as you are drain/fillling?
Once you have the in and out flow balanced, you take a 5 gallon bucket and take one of the hoses and fill the bucket while timing it. From that you get GPM, which you divide into the number of gallons you want to exchange and that tells you how long to run it.
Or, if you wish to drain fast and then fill, you can do that. The rental on the high speed pump will be the same cost as buying a lower powered sump pump.