Low CYA

[loweran]

All,

I tested today and my CYA is at around 25. I need to bump it up a bit. Here is the question:

I have some year old pucks that have been sitting, to my surprise, in a bucket half full of water. So, they are not completely dissolve. You think I could use them in a floater to get some CYA into the pool?

 

[jblizzle]

Well, this post certainly did not go the direction I expected.

I would imagine that is some potent water in that bucket that I would not want to put my hand it.

Is your water clear? If not, you may not want to bump up the CYA until after you shock.

If it is clear, then I think you should be able to use the tablets still ... although since they are partly dissolved it will be harder to know how much CYA is being added.

 

[carlscan26]

Do you need to shock? I don't think so from your post...

Anyway, it's a bit risky as you're not sure how much CL and CYA you have in there...if you do try this I'd pour off a small (and measured - maybe a cup) qty of that water water in the bucket into the pool in front of a return and wait an hour and measure the difference in FC (you'd have to measure before you added any of course). You have a plaster/pebble pool so if you did spike your FC you'll be ok you just don't want to spike your CYA. From this you could work backwards with the pool calculator to figure out how many oz of trichlor you just added and then work forward to see how much more you can add to get to your desired CYA.

As said above though, be careful handling this stuff; use gloves, eye protection, etc. And definitely don't do this if you're not comfortable with the process I described.

 

[loweran]

Sorry. Water quality and pool is spot on. The water is clear as air. Since coming here and getting educated, I have not had to shock except for the time a storm took all the tassels out of my huge oak tree and deposited them in the pool.

Here is the usual data:
FC: 3
CC: 0
TC: 3
PH: 7.5
TA: 80
CH: 220
CYA 25

I tested it a couple of weeks ago and got a 35 reading, but it was dark and overcast. Today I tested, not in direct sun and it was a clear reading of 25. We also have had a lot of rain and I had to dump around 5 inches of water over that time.

I found the bucket about a month ago, full of water, when I was working on one of my valves. I dumped the water that was in the bucket into the pool.

I suppose it won't hurt to try and raise the CYA with the pucks. I will monitor the chlorine and step the stenner back a bit while doing this. If it does not raise the CYA then no worries, I can buy some and add what I need. I think I am going to shoot for around 40 - 45. Summer here is long and hot and the pool gets sun from around 11:00AM till 8:30PM

 

[carlscan26]

Ok then treat the pucks like they're fresh for your calcs. Worst case you undershoot which is preferred.

 

[XsAllOverIt]

Nothing wrong with using pucks to increase CYA. Just so you know that you don't need chlorine until after you stop using them.

 

[carlscan26]

That depends on how much CL and how fast he needs it but as a general rule that's correct.

 

[loweran]

I will float a few and see where that gets me. Doubt it will add too much FC. I am running a min of 2.5 - 3 right now and am adjusting things back up for the season as the weather warms up. Dang water is already in the mid 70s.