Another One on Using Pucks to Raise CYA. Just curious!

[Cherie]

Our CYA dropped to 15 (or less) with the rains and drains in early May and again early June. (I had it at 20-25ppm since December and TA at 60 since late last summer, with pH holding steady at between 7.4 - 7.6)

We added a solar cover in June 1. We lost miniscule amout of water with the cover on and have only been using about 1/2 to 1 qt of 10% daily. Removed the cover from our "hot tub" a week ago (June 18).

On June 21, I tossed all three of our leftover pucks from the pool install last year into the floater to add whatever CYA it would add (yes, I now know it will only add a miniscule amount of CYA!) and have left it in the pool to see how long I could go without adding bleach...since I need CYA anyway and I'm faithful to check our water daily - in case I need to add bleach. And for the record, our CYA has hardly budged from 15!

So with our pool uncovered now and with 100 degree Texas scorcher, with the 3 8 oz pucks still tied to the middle of the pool, and with a CYA of 15, I'm only losing about 0 - 1ppm FC daily and am only adding a small amount of bleach when I feel FC may drop below 2ppm.

My numers are as follows:

Sunday, June 21:
During the a.m.: ADDED 3 8oz PUCKS
7:30 pm FC 2/0 CC
(evening: nothing added)

Monday, June 22:
11:00am FC 2/0 CC
8:00pm FC 1.5/0 CC (only lost .5 ppm FC today)
(evening: nothing added)

Tuesday, June 23:
7:00am FC 2/0 CC (not sure why it went back up - nothing was added)
7:00pm FC 1.5/0 CC (only lost .5 ppm FC today)
(after 7pm: added 1 qt 6% sorta - I spilled some :lol

Wednesday, June 24:
8:00am FC 2/0 CC
8:00pm FC 2/0 CC (LOST NO FC TODAY)
(after 8pm: added 1qt 6%)

Thursday, June 25:
08:00am FC 3.5/0 CC (not sure why it went up by this much!)
08:00pm FC 2.5/0 CC (only lost 1ppm FC today)
(evening: nothing added)

After seeing a few threads on here about using pucks to raise the CYA (and more truthfully, since the CYA needs to be raised anyway, why not just be really lazy about not having to add bleach each evening?), what would be wrong with using up left-over pucks throughout the summer to raise the CYA (however much they end up raising it, which will be miniscule of course!) and just keep an eye on your numbers to make sure you don't need to add a little bleach now and then?

I think that may be what some of the folks on here are asking, without asking it! When CYA is low already anyway, why not take advantage of the situation and have a lazy summer just using pucks all summer instead - making sure to have enough pucks to keep the FC safe and test the water each evening?

OK, that's about it. Thanks!

 

[PaulR]

If you have a supply of pucks, and your CYA is only kinda low, and it doesn't mess with your pH too much, I would go ahead with the pucks.

In fact I have done exactly that with the pucks! Overshot a little when I did my big drain. I knew, from before I saw the light, that the pucks would keep my pH dead steady; so, a couple months of puck use (supplemented with occasional cal-hypo for a little CH nudge) and my numbers are pretty decent now.

If the CYA is really low, the pucks won't be able to keep the FC up and you'll waste a ton of bleach helping them out. And if they keep dropping your pH it probably isn't worth the trouble either, although that's more of a judgement call.
--paulr

 

[frustratedpoolmom]

If you have pucks on hand from "back in the day" you CAN use pucks to accomplish what you want.

Like Paul said, the FC released might not be enough if your CYA is too low, so make sure you supplement with bleach to stay above your min. Also since the pucks are acidic, they WILL lower your PH and TA. IF you plan to use pucks you must monitor PH/TA and adjust them with soda ash while using the pucks. A higher TA like 120 will help buffer this somewhat.

You can use the "Effects of Adding Chemicals" section of the pool calculator to see how much the CYA and FC will be raised by "x" amount of trichlor tablets.

We don't advocate this method because of the side effects and it results in a slightly higher cost than straight bleach/cya, when you factor in the PH up products. But it can be used if you already have the pucks - I wouldn't recommend one go out and buy pucks for this purpose.

Also keep in mind that HTH Dual Action tabs contain copper, so always check the active ingredients on any chemical you plan to use in your pool.

 

[Cherie]

OK thanks Paul and FPM. So far, we don't seem to be losing much at all, given how low our CYA is. I've been surprised all week to see such little drop, given the heat from hades down here (so to speak ) My pH has dropped just a tad, but I figure I can throw the kids in the pool, sneak over to the neighbors and steal their kids and toss them in too and order them to have fun in the sun and that should take care of the pH for me My TA has held steady at 60 since late summer, but just went up to 70 - so not sure what's going on there. But that's ok, I want to keep it between 60-70 anyway.

So we'll just mozy along at this pace until I notice it's time to get back to BBB.

 

[frustratedpoolmom]

Have some borax or soda ash on hand - PH won't raise much thru aeration when your TA is that low.

 

[Cherie]

Oops! I forgot about that FPM! :? Yes, I ran right out last summer, after finding this site, and bought a box of borax and a HUGE bag of baking soda from Sam's Wholesale! I've never needed the borax - but may get to open it this summer! Thanks for reminding me. :-D