CYA question

[skydude]

I am fairly new to the site and have already learned a lot.

I ordered the TS100 kit and got the following numbers:

3.0 Cl
7.5 PH
550 CH
110 TA
100+ CYA

I used to use the floating pucks with weekly shock. I've since taken the floater out and purchased bleach and liquid chlorine.

The pool looks great right now. However, should I be concerned enough with the CYA level to partially drain the pool and refill it?

I had a local pool store test the CYA and they said it was at 120. They told me that level was perfect but from reading the forum I think 50-60 is more appropriate.

 

[Texas Splash]

It's very possible your CYA is actually much higher. Before doing anything else to your water, please do the following:

CYA Dilution Testing:
Add pool water to bottom of sticker.
Add tap water to top of sticker.
Shake.
Pour out half so mixture is to bottom of sticker.
Add reagent to top of sticker.
Shake.
Test outside with back to sun and tube at waist level.
Pour back and forth a few times to see if you get the same result.
Double the result.

Post that result so we can advise you further.

 

[skydude]

Just ran that test. With the 50/50 solution it hit the 90 line, so I guess it is at 180 PPM?

I just refilled the pool last year after I had pebblesheen put in, hopefully I don't need to drain the pool due to the high CYA levels. Although I'd rather do it before summer hits if necessary!

 

[jblizzle]

Sorry to say, but you would ensure much less likelihood of problems in the dead of summer if you replaced about 75% of your water now. (or 50% if you have a SWG).

Please add your pool details to your signature as described HERE as it will help us help you.

 

[Texas Splash]

That's a shame. Those pucks and bags-o-shock took their toll on that CYA. Ugh.

 

[skydude]

I updated my signature as requested.

Will some of the CYA burn off over the summer given that I live in Phoenix or is it more advisable to drain most the pool and refill it?

 

[jblizzle]

CYA does not "burn off". It can only really be removed by water replacement or commercial Reverse Osmosis treatment (which is an option for you). The RO generally costs a good bit more than just replacing the water.

The CYA does SLOWLY get broken down, but on the order of up to 5ppm per month, so that is not very helpful.

For reference, with a CYA of 180ppm, to keep the pool sanitized and algae free, you would have to maintain the FC above 14ppm at all times. And once the FC > 10ppm, you can not longer trust the pH test.

 

[skydude]

Ok, I have decided to drain around 3/4 of the pool water before the summer months set in.

When I previously drained my pool I would rent a submersible pump that I rented for $25 a day.

The pool I have now has two inlets underneath the skimmer basket. Is backflushing the pool an option?

 

[oldguy70]

I updated my signature as requested.

Will some of the CYA burn off over the summer given that I live in Phoenix or is it more advisable to drain most the pool and refill it?

I am in the same boat...living in the Sun/Heat, high CYA protects your FC, but then you may run in to other issues...but when you keep your CYA at 50-60 the use of chlorine skyrockets....a happy middle may be CYA at 70-80

 

[oldguy70]

Ok, I have decided to drain around 3/4 of the pool water before the summer months set in.

When I previously drained my pool I would rent a submersible pump that I rented for $25 a day.

The pool I have now has two inlets underneath the skimmer basket. Is backflushing the pool an option?

For $25 rent the pump..

 

[asusundevil]

I am in the same boat...living in the Sun/Heat, high CYA protects your FC, but then you may run in to other issues...but when you keep your CYA at 50-60 the use of chlorine skyrockets....a happy middle may be CYA at 70-80

Oldguy70,

I've always kept my CYA between 50-60 but am now questioning if I should consider your 70-80 being that I too reside in AZ. For how long have you been maintaining that CYA range? We burn through some serious chlorine in our state so any marginal modification to help salvage some is always appreciated.

 

[cowboycasey]

you can backflush/waste the water out, no issues doing it that way

- - - Updated - - -

Oldguy70,

I've always kept my CYA between 50-60 but am now questioning if I should consider your 70-80 being that I too reside in AZ. For how long have you been maintaining that CYA range? We burn through some serious chlorine in our state so any marginal modification to help salvage some is always appreciated.

That is always an option, in the "high" sun states with pools that get 100% sun and tend to lose a lot of chlorine during the day it may help to take you CYA up, I would take it up slowly and see where your pool likes it..

 

[pooldv]

Try raising your CYA by 10 ppm and see if you use less chlorine. If you do try another 10 ppm.