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View Full Version : Re: Chlorine Pucks vs Bleach - another pool with high CYA



smokeygrl
05-09-2006, 05:52 PM
Hello everyone. I have been reading much of the posts here and have learned alot. I have a pool in Eastern PA.
I opened my pool this weekend. 25,000 gallon gunnite. We have had it for about 3 years now. Every year I have used granulated chlorine to shock once a week and 2 trichlor tabs in the skimmers as maintenance. Last year I had a heck of a time trying to keep my chlorine up.
Now, based on what I have read so far, many of you know what I'm about to say....My CYA is ridiculously high!!! using an HTH 6-way test strip I have:
TH 400 - FC 0 - pH 8 - TA 180 - CYA 150

I shocked the pool initially on Saturday with 2 bags and added 2 quarts of Algacide. I have not yet backwashed.

Today I added 6 lbs of pH down. (3 hours later, didn't reduce it much)

I took a sample to my pool store. They say I need 6 lbs of pH down and 10 bags of shock and didn't say anything about the CYA.

Here's the thing. I know the stable chlorine did this to my pool.
I want to do something different this year but can't afford a SWC right now.

Please tell what you all think I should do - and in what order as it seems I have a couple of things going on here.

I am very curious about using household bleach. If I decide to go that route, what is the best and how should I start out using it? If I do use bleach, should I still continue with the trichlor tabs?

Help!!

Thank you.

Watermom
05-09-2006, 06:54 PM
You are right - your cya is way too high. It should be between 30-50. You can either do a partial drain to lower the cya level or you can live with the high cya but run higher than normal chlorine levels. See the chart at the following link for needed chlorine levels based on cya readings.

http://www.poolforum.com/pf2/showthread.php?t=365

No more pucks. Stick with only plain, unscented bleach. Generic is fine and cheaper. In a pool this size,
each half gallon (2 quarts) will raise your cl by about 1ppm.

Not only is your ph high, but your alk is high, too. The following link explains how to lower it.

http://www.poolforum.com/pf2/showthread.php?t=191
You also need to ditch the test strips (inaccurate) and get a good drops-based kit. You should consider getting the kit sold at the sister site to this forum www.poolsolutions.com as it can measure high cl readings which you will need to run with high cya. Most testkits that you can buy only measure cl up to 5.


Hope this can help you get started. If you have more questions, let us know.

smokeygrl
05-09-2006, 07:11 PM
Ok, Watermom, Here goes. I'm going to trust you and the Doc and jump in with both feet. No more pucks and granulated chlorine for me.
I'll go to the link you suggested and get my water balanced.....
Just a quick question., I am going to drop my pool level down once a week for about 4-5 weeks to drop my CYA. I figured a foot at a time ought to get me to 100ppm.
Will the CYA that's left in the pool help to stabilize the bleach I will be using?

Watermom
05-09-2006, 07:37 PM
Yes it will. Do not use any products which add cya. No trichlor, no dichlor. Only bleach. Using bleach really does a great job. I have never used anything but bleach in my pool. Keep us posted of how things are going.

CarlD
05-09-2006, 09:31 PM
To add to all of Lisa's good advice:
Don't use those bags of shock either. Mostly, they are Di-Chlor, which ALSO releases CYA into your water.

A CYA of 100 is what I would consider extremely high, but manageable. I like 30-50, but you won't get there this season. Still, if you dump 1/3 of your water, you'll drop CYA to 100ppm. You will need to maintain a MINIMUM chlorine level of 8ppm (that's the FC reading) at CYA=100ppm.

If your pH is staying high, powdered pH lowering (dry acid, no matter what else they call it) may not work for you. If so, muriatic acid is available at any hardware store. Dilute between a cup and a quart in 5 gallons of water, wearing eye protection and gloves and add that to the pool.

smokeygrl
05-10-2006, 08:32 AM
Thank you Carl. I need as much help as I can find since I'm a newbie to the BBB club. I'm a little upset that I thought I was doing the right thing by buying only stable chlorine for the past 3 years - turns out I was causing a problem - well, live and learn.
Anyway, I thought I had read on one of Pool Docs posts that you should bring the pH down slowly. So, should I start with about a 1/2 quart and expect to have to do that a few times before I come down to about 7.4 or 7.5?
Also, once I've got things all in proper chemical order (maybe next year) can some of you tell me what your maintenance schedule is like? (shocking schedule, etc.)
I'll tell you again what I have: 3 year old gunnite in Southeastern PA, 25,000 gallons. Thank you.

aylad
05-10-2006, 11:53 AM
As a general rule, it's always better to go slowly when you're adding chems to a pool--it's better to sneak up on your target number than it is to overshoot it! In your size pool, I would start with no more than 2 cups of muriatic, add it with your pump running (I usually just pour mine slowly into the return stream to help it mix), wait 2-3 hours, then retest and go from there. Be careful with the acid, because it's nasty stuff. wear gloves, glasses, and make sure you stay upwind of it. I usually hold my breath while pouring it-- it only takes inhaling the fumes once to make you understand why.

Your numbers aren't as far out as you think they are--with frequent backwashing/partial drains, your CYA and your Ca will come down to "normal" in no time! As far as maintenance schedule, mine consists of testing ph and Cl every couple of days, testing everything else about once a month, and adding bleach as needed to keep my Cl levels up. I shock after a heavy swim load or storms.

Get a good, drop-based kit. WalMart sells a decent beginner kit for about $15, but the kit Ben sells on this site is top of the line and is what most of us use. As an alternative, Taylor puts out drop-based kits that are similar and that can be found at your local pool store. In order to properly maintain your pool, a good, reliable test kit is an absolute MUST!

Welcome to the forum!

Janet

smokeygrl
05-10-2006, 03:15 PM
Thank you, Thank you, Thank you.
I've gotten nothing but great info from this forum.
I'll let you know how things work out.