CYA reduction Drained / Refill

[mdogan]

My initial CYA was more than 100 as per Taylor so, I'm not sure what was actual....It could be 120 to 150 may be more.

Drained %80 of pool and filled it up. Started running filter when water level at %50
At this stage added chlorine. 38oz ( estimated pool capacity 12000 Gallons)

When water reached level at %90, got tested at 50F temp (yesterday at around 4pm)

CYA was still over 100.

FC 9.0
CC 0.2
PH 7.4
TA 7.0
CH over 500 ( before started drain/fill that number was same, and supposed to be at last little goes down but result not changed)
CYA still over 100.

Dallas is cloudy nowadays and light was not enough when CYA test done.

Temp may impact the result?
and to reading more reliable CYA value, at last needs to wait 24 hours pool circulation ?

Thanks.

 

[AftonJeeper]

Wow.

Try doing step 8 of the directions listed here:Pool School - CYA

I don't believe temp or circulation are going to be an issue, but I'm not sure.

 

[kimkats]

It sounds like you have another drain/refill to do to get it down more The cya might have been higher than you thought.

Have you tested your fill water? Don't bother testing the CYA as it has to be added. I am wondering what CH your fill water comes in at.

If you can keep up with the FC levels with that CYA you should be okay to let it ride and work on it next month if you need to for your water bill. I don't know how yours if set up.

Kim

 

[Donldson]

It's best not to try guessing when the CYA is measuring above 100 because of the logarithmic scale of the test. Once the level is over 100 the scale gets so tightly spaced that it really can't be read correctly, which is why it doesn't go past 100. So baring a significant human error in one of the tests, it is entirely possible your CYA was over 500. In a location where pools aren't closed for the winter and especially if a service company was being used that is not unheard of.

 

[mdogan]

Yes, fill water CYA & CH already have been tested.
Fill water CH is around 300.

Before I started drain & refill, my idea was draining %75.

I got %25 pool %75 fill water mixed and checked CYA. was able to see around 60. Then drained %80.

Anyway, thanks for reply will go step by step %50-50 testing and see what needs to be done.
Maybe my CYA was over 200

Have a wonderful days

 

[needsajet]

It sounds like you have a functional main drain. If your pool water is colder or even the same temperature as your fill water, there's a good chance you can float the fresh water on top and draw the chemical laden water from the bottom. If it's successfully done, you can reduce your CYA with less total water.

Another member here put the fill hose in the skimmer box (water gently flowing out from the skimmer to the pool), and drew water from the main drain, at the same rate ideally, or at least somewhat slowly so as not to stir up the water too much. Might be worth a try.

 

[mdogan]

Yesterday I did one other FC test at 6pm and noticed that, there was no chlorine in the pool. I was happy
Then tested CYA and at this time have seen close to 30
I think, water circulation was not good or i did something wrong on first test, anyway....
Today weather was good, added chlorine in the morning and had one other test afternoon for CYA with nice sun

FC 4.5/5 (used by 0.5 )
PH 7.8
TA 80
CH 225/250 ( used by 25 )
CYA around 30..May be little less than 30 even...

With good sun light, i was able to see black dot with full of tube.

Now my question; Calcium is not stay on walls and my calcium number slowly will go up, no need to worry as per my understanding
But about of CYA; when I drained not cleaned the walls or acid wash, immediately refilled.
Any CYA stay on walls and slowly getting back to water? I do not want to add unnecessarily CYA

What is your advise ?

I think since water temp is low, better to keep PH around 7.8 and TA 80

Once again thanks to TFP.

 

[mknauss]

CYA does not stick around on anything. So what you are testing is what you have. Might want to add 10 ppm worth or so as you most likely have less than 30 ppm.

Not sure what you mean by calcium not stay on walls?? Do you have scale on the walls of the pool?

Could you put what country, state, or province FRISCO is in. Helps us to know the climate you are dealing with.

Take care.

 

[mdogan]

No, there is no scale on pool walls. I meant similar of CYA, CH stick on walls? but got the response. Thanks
I will check couple of more days and see the daily used FC and depending on daily usage, add 5 to 10ppm.
I live in Frisco TX. It is 40 min drive to North of Dallas.
Thanks Mknauss.