Give it a couple hours to make sure everything is well mixed. You should probably test your CYA again to get an idea of 1.) How much did it go down and 2.) How much you still have to go. An example, say it dropped you from 180 to 90, then you know you still need to bring it down and that you drained about half of your water. So you will know to drain just a bit less this next time to get it to around 50.
Green Pool
- Thread starter Zegster
- Start date
Anybody? How long do I circulate the old water with the new awater?
nevermind was answered. Was replying when you sent the previous message.
nevermind was answered. Was replying when you sent the previous message.
How much do you think I drained. If I drained 3 ft from the 4ft shallow end? 50%? Its 8 ft in the deepend and 4 ft in the shallow end.
A lot depends on how much of the pool is at 4' and how much is at 8' and how much is sloped. If it was a continuous slope, your average pool depth is 6', so by draining 3', you removed 50%. But it probably isn't a continuous slope, so it gets difficult. I could crunch numbers and come up with a close approximation if I was there with a tape measure, but I'm not, and trying to teach geometry via forum postings just doesn't work.
The best way to tell is by testing.
When I was replacing water last year to get my cya down, as soon as it reached the skimmer so that it wouldn't suck air, I started my pump to recirculate and filter the water until it got up to mid skimmer then started the next drain. Making sure I turned off my skimmer valves so it just drained from the bottom drain. I also used backwash to drain-- no reason to not clean the filter in the process. If you have a vacuum, you might want to make sure that the boost pump doesn't start while you're draining. Unfortunately, I hadn't thought of that and I locked up my boost pump irreparably. Remember though I was going to do 5 drains so I didn't worry about testing my cya until after the the drain. I figured draining 3 ft in the shallow end of your pool would be draining about 11,500 gals, so you really do need to retest before you start your second and probably final drain. That should tell you about how many inches you need to drain for it to get you to 50. Though, I'd figure it will be close to 3 feet again. But that's why you also need to know a more exact capacity for you pool.
How would I tell the capacity of the pool? Its 4 ft shallow and 8 ft deepend. 16x32
Break out a tape measure and start measuring depths and lengths. Break it into three sections. The shallow part, the sloped part, and the deep part. The best you'll get is a close approximation, since there are no doubt rounded corners to deduct, and steps that take space, and whatever water is in the plumbing and filter.
Don't ya think I should just drain and refill one more time before testing my CYA. So I don't waste the tests? I just ordered 4 more bottles of the cya reactant. But it looks like I only have enough to do 3 more tests right now. I found out my pool is 3 ft in the shallow end and 8 ft in the deepend. Its your standard pool. I looked it up and 21,600 gallons. That's what my pool store told me too. I calculated that I only drained about 35%. So my cya level is probably at 117. So I think I am going to drain and refill one more time. Then test. That should get it to 76. Then I'll test and probably do another drain and refill and that should be 50.
Those numbers are what I figure now too, considering now actually draining and replacing 2 ft of water each time instead of 3 ft. You should test it when you've replace it to what you think is the 76 then test it to find out what your last drain needs to be. Remember, those are all rough estimates until you actually do that test. I'd use that 21100 gals as your capacity (that's using the average depth of 5.5 ft) or maybe stick with 21000 even as you had before in pool math without trying to do all those detailed measurements.
Ok, I have emptied 35% and refilled twice. I did the test and first I measured 90. Then I waited 30 seconds and could still see the black dot. Then added more and then it came to 52. Is it what you measure first?
That's the good thing about the cya test. You can put it back in the mixing bottle and redo the test. Do it as often as you can to get consistent results. Also, getting an exact amount of drain and refill is very difficult to do. Looks like you may have drained more than 35% at least once. Also pool capacity measuring is pretty inexact as you've found too. Best you can do is a ballpark estimate.
Ok, I put it back in the mixing bottle and got 60 and then did it again and got 70. Now I need to figure out how much to drain for my last time. I am filling while draining. So it actually might be more than 35%. So what is the recommended cya level to get too? I figure if I drain 35% again and stop it from refilling this time it would bring my cya to 65 * .35 = 42.
60 and 70 are not consistent results --do it a few more times or as often as necessary to get the same result. Then figure from there. Filling and draining at the same will never get an even close amount of how much you've replaced!!!! I lived in Bellevue a few years and know how sunny and hot summers are there. 50 would be a good target for you.
I did it again and keep getting around 60.
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Also what is the recommended cya level?
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Also what is the recommended cya level?
See my edited post above! Then 60 it is! Give me a minute and I'll figure it for you.
Ok, I will drain little less than 1 foot. That should be 10/60=20% I figure I have been draining 40%-50% every time.