CYA sky high but other parameters are ok?

[gus6464]

Hi everyone,

We moved into our new house 3 weeks ago and this is first time with a pool. I have a reef tank and have had plenty of freshwater planted tanks so testing constantly doesn't bother me so decided to take a stab at maintaining the pool myself. The previous owners had a pool guy. I got the Taylor K-2006 kit and have been keeping my parameters like so:

FC - 3
pH - 7.6

The only issue is that my CYA is sky high way past 100. I am in San Diego so draining half the water and refilling is not going to happen. The thing is that I have not had any algae issues and I am using about a pint of 8.25% bleach per week and a 1/4 of a gallon jug of muriatic to keep my pH from spiking. There is also a chlorine tab on the floaty at all times. Based on what I have read in the stickies my FC should be a lot higher and I should be dumping a lot more bleach to keep up with demand but that hasn't been the case and I have no algae. The pool is ~14000 gallons. Is my test kit just off for the CYA?

 

[Texas Splash]

Hello Gus and welcome! Well, yes, your biggest challenge will certainly be the high CYA. Anything over 100 and it's hard to know what is really is. Since you can't drain, you are somewhat guessing as to what FC is required to align with that CYA based on this product Pool School - Chlorine / CYA Chart. You can see the important of the two aligning together. So, to help you better know what your CYA "may" be, try the CYA diluted method:
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.

At least this way you may know better what your CYA is. Also, remove the tablets/pucks. They raise CYA. You don't need that. Stick jut to the regular household bleach. It's virtually pure sanitizer. If you still have a concern about how to perform the CYA accurately, let us know and we can help. Have a nice day.

 

[duraleigh]

Welcome to the forum.

I am in San Diego so draining half the water and refilling is not going to happen.

Well, that will be a dilemma. Assuming your CYA test is correct, you are operating your pool in a situation we think of as unmanageable.

That much CYA has rendered your chlorine pretty much ineffective and if you do get an algae bloom, the amount of chlorine to fix it will be eye-popping.

The best scenario is that your CYA test is in error but if that dot disappeared before you got to the 100 mark, it's a valid test.

There is also a chlorine tab on the floaty at all times.

and that just makes your situation worse as the CYA from those tabs continue to go into your pool water.