Testing basics


Active member
Jun 3, 2008
West Grove, PA
I am officially taking matters of my pool into my own hands and will be relying on info from this website. (insert cheers here) I have had it with the advice from pool store "professionals" in my area. I can't go through another season of conflicting opinions and drastically different test results, but I'll need a little guidance to get me off the ground.

Had a problem last year with keeping the chlorine levels up. (no need to go into details) Problem has started again this year. Will be ordering one of the recommended test kits so that I can get test result myself and try to be consistent. :) Until this arrives, i would like some guidance on where to start.

AG Vinyl pool
~10,000 Gal
tri-chlor pucks in feeder
Readings averaged from 2 different pool stores over last 24 hrs.

Need to know where to start to balance the water. I'm thinking of adding CYA first. I have 2.5lbs and plan to add 1.5lbs initially to see where it goes. Once that is in range, retest and work from there. The water is clear but seems to have a slight green tint and i'm trying to keep the algea at bay while balancing but don't want to waste the chlorine.

Am I on the right track?

Thanks in advance

Kurt :?


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Hi, Kurt,

Welcome to the forum...you'll never look back.

First off, you're almost surely gonna' burn up more chlorine than you a currently prepared for. You have an algae bloom in your pool and it will take a lot of chlorine to get it out.

Secondly, it is very difficult to do this process without having a really good test kit that will measure Very high chlorine levels. My suggestion would be to not even start the clearing process until you make the decision to get a kit. The Taylor K-2006 and the one I sell and Leslie's FAS/DPD kit are the three best on the market.

Get a kit in your possesion, stock up on at least 10-15 gallons of clorox, and then post up your own test results......lot's of folks here will guide you thru the process.

Meanwhile, you could safely put 2 quarts of Clorox in your pool each evening until your kit arrives....It'll help keep the algae in cheack and may actually start to clear your pool.

Hold off on the stabilizer for a couple of reasons.....it'll come in after your pool is crystal clear....and it will be!! :lol:


TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
SWSuburban Chicago, IL
If he's got Tri-Chlor pucks in his feeder, he's adding stabilizer, because the pucks have CYA in them.... when you say "feeder" what exactly do you mean?

Dave's right; get a good kit and calculate your shock level for Chlorine. Because until you post truly accurate numbers it's hard to tell you what to do next. BTW Don't necessarily buy "clorox" if you can get a store brand bleach or pool store liquid shock on sale that works too....

And have a dose of POP, Pool Owner Patience. They prescribed it to me a year ago, and it is a necessary medicine for the process... Good luck!!!


LifeTime Supporter
Jun 26, 2007
SF Bay Area

Are you sure about your CYA = 7.5 number? A couple of things concern me on this reading.

1) 7.5 is a very strange number. Most CYA tests seem to jump in 10 digit increments.

2) If you have a tri-chlor puck feeder, then you have been adding CYA to your pool with every puck you add. Unless you did a COMPLETE drain and refill, then I would think you would have a much higher CYA number that you inherited from last year.

How did you get the CYA = 7.5 figure?

Good luck.



Active member
Jun 3, 2008
West Grove, PA
I have 3 gallons on hand, but the pool is greener than when I left for work this morning. I guess i'll be using it to keep it at bay for now. I have the small OTO kit, which i swithced to last year from strips but obviously it only measures to 5ppm. The decision is made to get the "real" kit, just have to get one in hand. I figure that the money I'll save in gas to get pool store advice and subsequent chemicals will pay for it. I heard it all last year, phosphates, chlorine lock and so on... I could have laid $20 bills on the pool surface and gotten the same result. I've heard of POP and will have to reach down deep to find what's left of mine. It's way too early in the season to begin this frustration.

I have an inline "feeder" (with 2 pucks in it currently, set to MAX) between the new Hayward C900 Cart filter and the return. I do realize that the pucks contain stabilizer, which is why I didn't want to do anything until I asked for some sane advice. The pucks take so long to dissolve that I figured it would take forever to raise the CYA. When you mention the correct shock level, you're referring to getting a good reading from a test kit on the CYA, FC & AC then using Ben's best guess chart to determine how many ppm I'll need to get to for an "effective" shock treatment, right? I'm trying to absorb as much info as I can...

Clearing the pool (with the right amt of shock) will actually raise the CYA? You're probably used to the initial skepticism, right?


Active member
Jun 3, 2008
West Grove, PA
PS... the 7.5 CYA reading was an average of the 2 places i took the water to. Leslies said 5PPM and a local pool/spa place said 10PPM. I just averaged for simplicity.

What's the difference between the Taylor 2005 & 2006. I've seen the 2005 locally for $63.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Some kinds of chlorine have CYA and some don't. Trichlor, commonly used in tablets/pucks/sticks, has CYA. Dichlor, commonly sold as granular "shock" has CYA. Cal-hypo, commonly sold as powdered shock, doesn't have CYA. Bleach doesn't have CYA.

The Taylor K-2006 has the FAS-DPD chlorine test, which is crucial for measuring high FC and CC levels when shocking. The K-2005 has the DPD test which can only read FC and CC up to either 5 or 10 depending on how you do the test, and can be misled by very high chlorine levels.


TFP Expert
LifeTime Supporter
May 30, 2007
South Carolina
Hi klavant,

The best investment we made in our pool was a good test kit. This will put you in control of your pool. I recommend the TF Test kit sold by duraleigh, one of our members. He uses Taylor regents and has outstanding customer service! Link in my sig.

When you have time, please add all your pool and equipment information in your signature. This will help members respond more accurately to your questions.

Welcome to the forum :lol: