CYA and draining my pool - First post ever. HELP!!!

[Barefootwithme]

My pool has a case of the Mondays...

I just started the BBB method last week (awesome) but am still wrestling with high CYA thanks to those dumb chlorine hockey puck things. My CYA is currently 100 and I'm having to keep my free chlorine at 5 to manage. I feel like I'm running uphill.

So...it appears my only solution is to dump water and refill. What are my options? Should I:

* vacuum to waste 50% of my pool and THEN refill? (12,500 gallons would seriously flood my yard)
* vacuum to waste WHILE I refill for a few hours and see what happens?
* Try to do this in stages? (20% a day for a few days)

Any help is appreciated!!!! Thank you!

 

[Richard320]

Welcome!

If you have the valves such that you can draw from the drain only and send the water out to waste, that's the easiest way to do it. As long as you're not battling an algae bloom, doing it in stages will work. Figure out your average pool depth and then reduce it some percentage and then refill. Estimate the remaining CYA based on percentage exchanged and maintain FC for that CYA level until next week.

As an aside, your CYA may be higher than 100. The lines get awful close together down at the higher levels. Retest using the dilution method if you haven't already. Step 9

 

[DaninFLA]

well, your CYA is 100+, it could be 100, it could be 300. you don't know until you do the diluted test that Richard recommended above.

as far as draining goes, I highly recommend you just bite the bullet and do one drain and refill, assuming you can. first thing to check is the water table, you don't want to drain the pool water level much below the groundwater table, doing so could float your pool. that would be bad. real bad.

most reliable way to determine your water level is to dig a hole next to your pool, as close as you can. dig the hole down 3-4 feet and then let it sit. if it fills up with water, the level it fills to is your water table. don't go much lower than that. if the hole stays dry. you can drain to the bottom of the hole level.

one larger water change is going to save you time, money and aggravation. its so much more efficient to do one water change. one 60% water change does not equal three 20% water changes. for a 25k gallon pool, a single water change will take your CYA down 60% and will cost you 15,000 gallons of water. three 20% water changes will lower your CYA by 51%.

with your CYA I would do at least 60% water change first (if you can), then retest and go again. if you can do 70%, even better. but check the water table

 

[Barefootwithme]

Thanks guys!! This whole CYA thing is intimidating. I got the measurement from the local pool store that does a digital scan (they actually read it at 103). Are those more accurate?

The whole water table thing freaks me out too. My parent's in-ground plaster pool was floated because of that! I know it's not as efficient, but I'm going to do a little at a time. Maybe the 3 20% water changes and see if that helps. I'll let you know what happens!!! Thanks again!

 

[Texas Splash]

As you prepare to drain, refill, and test your CYA in the future, remain confident in your own test kit. We place very little confidence in any pool store testing. If you have a questions about your Taylor K-2006 or the CYA test specifically, let us know and forum members will be glad to assist. Good luck!

 

[DaninFLA]

Thanks guys!! This whole CYA thing is intimidating. I got the measurement from the local pool store that does a digital scan (they actually read it at 103). Are those more accurate?

The whole water table thing freaks me out too. My parent's in-ground plaster pool was floated because of that! I know it's not as efficient, but I'm going to do a little at a time. Maybe the 3 20% water changes and see if that helps. I'll let you know what happens!!! Thanks again!

don't go to the pool store and don't let them test your water. you have the K-2006, more accurate. do it yourself and post results.

 

[pabeader]

also, 3 20% drain and fill is not the same as 1 60%.


3 20% leaves you at around 51
1 60% leaves you at 40

 

[Barefootwithme]

Wow! Thanks for the quick responses! This is all useful information. I'm in the process of doing a few draining/filling cycles to see if I can get the CYA down.

Will switching to unstabilized chlorine (bleach) have any affect on reducing CYA? I'm assuming that using the 3" chorine pucks (stabilized chlorine) got me into this mess in the first place! If you continue to use the chlorine pucks will your CYA continue to rise?

 

[Barefootwithme]

As you prepare to drain, refill, and test your CYA in the future, remain confident in your own test kit. We place very little confidence in any pool store testing. If you have a questions about your Taylor K-2006 or the CYA test specifically, let us know and forum members will be glad to assist. Good luck!

Confidence is what I need. The pool stores make me feel like an idiot. When it comes to CYA testing, do you wait until you can't see the black dot at all? It seems like more of a subjective (and confusing) test. Basically if it's over 100, my test doesn't tell me how much over.

 

[Texas Splash]

That's why we're here. All of us post to help others like you because we were once in the same position. The nice thing about regular bleach is it has no side effects (i.e. stabilizer) like other products. So you just pour-in whatever is needed to maintain your FC level. That's it! Your CYA won't go down on its own unfortunately. The tablets, pucks, and "bags of shock" have done their damage, so other than a little water splash-out (cannonball!), the only way to reduce CYA is replacing the water. But that's okay, you'll get there. Many of us also had CYA's well over 100+.

Yes, the CYA test is a bit subjective. You do want the dot to disappear, but we understand how it plays tricks on your eyes too. Some of us pour the mixed solution into the tube and get our first reading, then pour it back to the mixing bottle, mix a second time, and do another reading. Sometimes I do it 3xs. Just helps my eyes adjust to get a good confident, repetitive reading. You'll get it. And you are correct, if it's over 100, then you never really know "how much" over 100 it is. But at least now you know what to do and YOU are in control.

 

[Richard320]

Wow! Thanks for the quick responses! This is all useful information. I'm in the process of doing a few draining/filling cycles to see if I can get the CYA down.

Will switching to unstabilized chlorine (bleach) have any affect on reducing CYA? I'm assuming that using the 3" chorine pucks (stabilized chlorine) got me into this mess in the first place! If you continue to use the chlorine pucks will your CYA continue to rise?

SWitching will not lower CYA, but it will stop it from increasing. CYA is the STD of the pool world. Pucks are so easy, but they leave behind something that is really hard to get rid of.

 

[Barefootwithme]

Okay!!! Here's an update! I did two partial drains (roughly 20% each time) and got the CYA down to 70!!! Woo hoo!!! I've run out of CYA test reagents and will be getting more this week to test again. I've stopped using pucks completely so the CYA shouldn't be increasing at all. Also, I've vacuumed to waste/refilled a couple of times since my last CYA measurement so I'm hoping it's down even more. I'll keep you posted! Thanks again for all your help! You guys are awesome!

 

[tim5055]

How does the pool look?

IF your pool is clear you can live with high CYA, it's just not perfect. I'm about 2 hours south of you and live with CYA above 200 because I had a clear pool. You just have to be diligent about keeping the chlorine levels where they need to be. With 70 CYA your chlorine should NEVER go below 5, which means you really should target 8 or 9. It sounds like a lot to people who have only dealt with a pool store saying "keep it between 2 - 3", but remember most of the chlorine is being "held in reserve" by the CYA.

I took me 18 months to slowly work my CYA down. Aggressive backwashing, a few partial drains and harvesting rainwater from a roof gutter got me to my current 50.

 

[Barefootwithme]

How does the pool look?

IF your pool is clear you can live with high CYA, it's just not perfect. I'm about 2 hours south of you and live with CYA above 200 because I had a clear pool. You just have to be diligent about keeping the chlorine levels where they need to be. With 70 CYA your chlorine should NEVER go below 5, which means you really should target 8 or 9. It sounds like a lot to people who have only dealt with a pool store saying "keep it between 2 - 3", but remember most of the chlorine is being "held in reserve" by the CYA.

I took me 18 months to slowly work my CYA down. Aggressive backwashing, a few partial drains and harvesting rainwater from a roof gutter got me to my current 50.

Hi Tim! I'm from Columbia! In fact my parents still live there (with a pool of their own). How are you surviving the heat? Our pool has been around 85 degrees all summer. I have large groups of little kids that come over and keeping the FC level up is a chore. Feel like I'm buying out Walmart when I get bleach. That said, the pool looks great now. I had the beginnings of an algae bloom two weeks ago but caught it in time. I had let the FC dip below 5.

Right now, here's how I'm testing:
FC - 7.5
CC - 0
PH - 7.4
Alk - 80
CH - 170
CYA - 80. Yes. It's not 70 like I thought. I've tested twice more and it's closer to 80. I'm going to dump some more water next week to try and get it back down!

Thanks for your help!

PS - according to the Taylor K-2006 Watergram wheel,my saturation is between -.03 and -.04 (at the current water temp of 82). Taylor says a saturation index of -.03 or less could be corrosive to concrete, plaster or metal surfaces. Should I be concerned?

 

[Pogueld]

If you play around with the pool math calculator on this website, you can play around with the CSI and see what to adjust to get it to a better level, but let's be sure your water is clear first and worry about that later.

How does your water look? Can you see the bottom clearly?


[emoji176] Lisa P.
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