Replacing water to get rid of CYA

[bbb]

xcapecod83 - duraleigh's questions are excellent ones. Also, is your pool plaster or vinyl liner? If it is a vinyl liner pool, my understanding is that you have to be extra careful to keep your pool at least 1/3 full in order to keep your liner in place. Also, what method did you use to test that your CYA is 150? Are you positive it is that high?

[salinda]

Honestly Larry, my cya was easily as high as yours for the last two years. I dumped the pucks and went with liquid chlorine (before I found this forum--I actually got that advice from a smart person at a local pool store whose name starts with "L"!). It dropped a little last year. Then I put in an SWG so I didn't have to deal with chlorine (only acid) from then on. I started draining the pool but gave up because I know our groundwater is high here. There are several creeks in my neighborhood in N. California and I got nervous.

From this forum I learned that if I didn't have an algae problem, I could simply run a much higher free chlorine level and things should be okay.

Mother Nature took care of it this winter. The rains and chlorine demand from the winter debris dropped the CYA naturally and it is now 40!

Also, I do have a small ball valve with a hose bib connection installed on the pressure side of my circulation system. There is a sewage cleanout nearby so I can run a hose over there for winter draining. I can drain the pool through this as well, but it takes a loooooong time.

[CarlD]

Al,
With a cart filter he may not be able to vacuum to waste. It seems a lot of pool installers, when they install carts, don't put 3 way or 6 way valves on them. My dad didn't have a valve for his DE filter, but the filter had a bottom drain he could use to flush it.
Do Carts have such a bottom drain?

[salinda]

I have a cartridge filter and you are right, there is no multiport valve for the filter. There is a drain port at the bottom of the filter.

[xcapecod83]

Thanks for all the great information! My cartridge filter cannister has a drain plug so I can drain the water when I clean the filters. It's too big for a hose, but there's a drain near by. Can I drain water this way without damaging my system?

[salinda]

I don't know about draining through the plug. Maybe you can....

What I have is a brass ball valve with a standard hose bib thread on it plumbed into my system between the heater and the filter. I run a hose from that to a nearby sewer cleanout. With the pump on, I open the valve and it can drain the pool very slowly. Of course, I turn off the autofill with this setup. I am thinking that if I left the autofill on and closed the skimmer, I would be draining from the bottom and filling from the top I can do a suboptimal water change that way too.

Moot point for me since the rain dilution this year took care of the problem.

[xcapecod83]

xcapecod83 - duraleigh's questions are excellent ones. Also, is your pool plaster or vinyl liner? If it is a vinyl liner pool, my understanding is that you have to be extra careful to keep your pool at least 1/3 full in order to keep your liner in place. Also, what method did you use to test that your CYA is 150? Are you positive it is that high?

I'm using the CYA test in the Leslie's DPD test kit (the one where you add water until the black dot at the bottom of the cylinder disappears). I checked it twice.

[bbb]

I'm using the CYA test in the Leslie's DPD test kit (the one where you add water until the black dot at the bottom of the cylinder disappears). I checked it twice.

Great - I was hoping you were using the black dot test. I just wanted to make sure you were using the proper test, and not just a pool store printout or test strip, before going through all the effort of a drain/refill. As others on the post have said, if you get the CYA down between 50 and 100, you can certainly successfully run the pool (using the higher Cl amounts suggested in Ben's "best guess" table), so make your own judgement about the target level based on the amount of effort you want to put in, the cost and quality of your fill water, etc.

Good luck!

[grangerhj]

I have been battling an elevated CYA for the past month- found out it was elevated by chance- my pool store must not have tested for it because I never was told it was a problem. Reading of around 150. Have a fiberglass pool and was told by installer that I could not empty it more than 12 "- I have done that twice with very little inmprovement. I waqs swimming in the pool- which looks great by the way, I just have to keep using chlorine- am I in any danger using the pool?:

[cygnusecks]

Couldn't you simply use two hoses: one is siphoning water out while at the same time a different hose is adding new water? This wouldn't remove CYA as fast (and you'd waste more water) but this would avoid having to empty the pool at all...

I've never needed to drain so I'm just hypothesizing that this method would work.. wouldn't it?