CYA High

[tjk15]

Hello all, I'm new to the board and fairly new to pool care. I've already learned a lot by reading different threads on this board. Thanks y'all!

My problem is green algae. We treated for that a couple weeks ago and thought we'd solved the problem only to discover it keeps coming back. Finally had time to research and investigate further and have come to the conclusion that our problem is due to very high CYA (above 100) likely a result of the trichloro tablets we use in our automatic system, but not 100% sure.

So my question is, is the Taylor CYA test reliable enough that I should be confident in that finding and if so, is my only (or best) option to partially drain and refill the pool?

I hope I've given adequate information, but if not, I'm happy to provide more details.

Thanks in advance!

TJ

 

[Patrick_B]

Welcome to TFP!

Sure it's accurate enough, no worries there. If you have the option, I would drain to get the Cya down to 30 or 40 and perform a full and complete SLAM on the pool. Which test kit do you have?

 

[tjk15]

Welcome to TFP!

Sure it's accurate enough, no worries there. If you have the option, I would drain to get the Cya down to 30 or 40 and perform a full and complete SLAM on the pool. Which test kit do you have?

Thanks for your response! We're using the Taylor K2005C test kit.

How can I know how much water to drain in order to get CYA down to 30-40?

 

[swoopman]

How can I know how much water to drain in order to get CYA down to 30-40?

Pool Math to the rescue, it's awesome:
http://www.troublefreepool.com/calc.html

 

[AprilsZoo]

In order to do a SLAM to totally eradicate the problem you will need a DPD-FAS supplement kit to test the chlorine levels that will be required...
Your kit, the k2005 has everything that's recommended except the DPD-FAS. That supplemental kit can be purchased separately for, I think, $20-25.

Your kit is very nice, but can only accurately test chlorine to around 5, if I'm not mistaken. A SLAM process will need FC levels of 4 or more times that, in order to completely send your algae packing for good!

 

[tjk15]

So another question, after I've drained the water to lower CYA, then SLAM, at what point is the water consider safe enough to swim?

And beyond that, if we discontinue the trichlor tabs and opt to use liquid bleach instead, how often are y'all having to add bleach? Daily? Weekly? I know the exact time is going to vary, but just in general?

Thanks in advance.


TJ

 

[Patrick_B]

Once SLAM is fully completed you can swim when the FC level drops a point below shock value for your Cya level. It's safe to swim up to, but not over that. As for frequency of additions, it depends on bather load, Sun Exposure time, the amount of organics that get into your pool, etc. All are are different, but plan on every two days, bare minimum. I get a lot of shade, and often go three between additions. Test and add daily until you get a true feel for how your pool behaves, and what it requires. That usually takes people a few weeks, sometimes less. In time, you'll be able to predict with reasonable accuracy what your pool is going to need, no matter what's been going on. Once you get there, you are going to be amazed how easy it is to keep a perfect pool. This happens time and again with members here, and you'll see it for yourself first hand I promise. You'll need some patience to work through SLAM, but it will be a success if you follow through I assure you.

Save the Tabs for vacations, or periodic use just FYI.

 

[tjk15]

Thanks Patrick! My husband and I greatly appreciate the help.


TJ