Big CL Demand/CYA Process time?

Happy Mothers Day!

found out yesterday I have 7 CYA & my pool consequently hasn't been holding CL @ all! I slowly poured in 6 llbs to the skimmer in day & @ night poured in 2 gallons of 10% bleach , wake up this morning to find same exact low CL reading of 1ppm ??

I have an unusually large skimmer that if I reach into w/ my arm all the way extended , I still can't reach the bottom! I noticed alot of the CYA acid sitting @ the bottom of the skimmer so I worked it up into the filter (still some on bottom)

my question is how long does it take for the CYA to take shape & guard the CL? Don't want an algae bloom & I'm hovering on 1-2ppm 20k gallons/ 85 deg

here are my numbers & thanks!


FC 0.1
TC 0.2
CC 0.1
PH 7.3
CYA 7
TA 178 - high :(
CALC 385 - high :(

Everything I have read and been told is that when you put CYA in your pool, you dont test or add more of it for around a week. CYA desolves very slowly and will take about a week

Boyd's info is correct...it'll take a while for the CYA to show up. You also did the right thing by getting out of the skimmer into the filter...that'll speed up the process. Don't backwash 'til your CYA test reads about 30 -40.

Meanwhile, you are also smart to keep putting in Cl of 10% every evening.....it is being consumed by bad stuff...probably algae you can't yet see. Test each evening for Cl before you put it in and then put in enough to bring your total up to 10-15ppm.

The "bad stuff" eats the Cl at night and, 'til your CYA takes effect, the Sun eats your Cl during the day. It may not seem like it but you're doing all the right things and you'll stabilize soon.

Thanks for those numbers. You can work on the Calcium and Alk in another post.....you do not have a harmful situation with either....just some fine tuning to do.

This is the way I have been adding CYA and it works a lot faster than using the skimmer or filter.

http://www.poolforum.com/pf2/showthread.php?t=1139

Pat

Pat that sounds like a pretty good method, I am about to have to add some cya and will give your method a try

thanks 4 the help !!
KE;)

ok cool, =but I'm burning through 2 gallons of 10% liquid bleach every night @ this pace!! Pool always tests @ around 0-1ppm the next day.....could just warm water eat up CL? we swam yesterday , but the majority of the days are covered w/ a Coverstar top. I forget what is average during hot days for CL consumption, but I don't remember it going this fast! thanks, hope the CYA police show up soon!

Is this a new pool or one you just opened...if you just opened it what was the CYA on closing? The reason I ask this is that there are bacteria that can eat CYA in a closed pool and "poop" ammonia compounds which create a HUGH chlorine demand. If this is the case you might go through a lot of chlorine before it holds even with adequite CYA. You are not specifying whether the chlorine readings you get the next day are FC or TC. If they are FC I would be interested in what your TC readings are. If they are high then so is your chlorine demand.

Your initial readings of 0.1 ppm FC and 0.2 ppm TC look like pool store readings since drop based kits don't give numbers like that. (Your numbers look like they came from the LaMotte Waterlink Express or similar colorimeter)

What are you testing your water with at home to get your chlorine readings? OTO, DPD, FAS-DPD, Test Strips? (If you don't know then just let us know what test kit you are using.)

This info might help the folks on here get a better handle on your problem.

You need patience to let the Chlorine do its work. I can remember back in February when the pool cover was on because the new pool screen had not yet been installed.

I added 45 lbs of shock to get the pool water to change color, after I had spent a week removing all the debris from pool bottom.

Keep adding the liquid bleach, and you will start to see results. Things just do not work that fast when it comes to pool maintenance.

Once you see the "CYA Police" start to take effect, you should see the difference. Hang in there and you will see the difference.

Hope I have allayed some of your concerns.

Pat

I'm using an OTO Walmart kit, picked up Ben's few days ago (awaiting) & will post soon

pool was opened in late April .....CYA was normal as far as I remember last year , around 50

pool looks a bit cloudy...algae cometh....& I'm buying bleach like the wash boy for the SF 49ers

dumped in a bunch tonight & later reading was 2PPM....seems very difficult to not let the level "yo yo" as Watermom puts it.....

thanks!

You are right, it is difficult, but that is the key to killing algae. That is why we say test 3x a day and each time shock it back up. Actually, you can test/shock more than 3x a day if you have time.

Quote:

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Originally Posted by h20man

I'm using an OTO Walmart kit, picked up Ben's few days ago (awaiting) & will post soon

pool was opened in late April .....CYA was normal as far as I remember last year , around 50

pool looks a bit cloudy...algae cometh....& I'm buying bleach like the wash boy for the SF 49ers

dumped in a bunch tonight & later reading was 2PPM....seems very difficult to not let the level "yo yo" as Watermom puts it.....

thanks!

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If you closed to 50 ppm CYA and opened to 7 ppm then you probably have a lot of ammonia compounds in your pool from the biodegration of the CYA. This is part of the reason for you huge chlorine demand. The algae is possibly the second part. Until all the stuff that is consuming the chlorine is gone you just have to keep putting in more until it start to hold. Just have patience and have a lot of bleach on hand and it will eventually burn it all off, kill the algae, and you will be swimming soon. Watermom has given you sound advice! Try to follow it as best you can.

I'm a drummer , not a chemist !! well....a part time pool guy now....thanks 4 all the advice, I'm on it... I've never seen a pool eat CL like this...just dumped in 2 gallons of 12.5% CL & did a test 45 mins later & 1ppm!!!
CYA is up 22 now
:rolleyes:

It's going to be eating chlorine until the chlorine demand is statified. Sorry if I got too technical before but I was trying to explain that there IS a reason why your pool is temporarily 'eating chlorine'. It's very hungry for it right now!;) Just be assured that if you keep following the good advice you've been given so far and have a little patience and a LOT of bleach:D your pool will soon be back to normal.