Chlorine Pucks

[donfranko]

Any opinions on brands of Chlorine Pucks?
I usually use them in an in-line feeder to supplement BBB until CYA gets to an acceptable level. In previous years I remember reading posts about additives in certain brands. thanks

[waterbear]

HTH (and some others now) are putting a small amount of copper in their pucks so they can call them multi-purpose or dual action. The copper really isn't enought to be algaestatic unless you use them for a very long time. Look for pucks that do NOT have additional ingredients listed on the label (unless is is only sodium tetraborate, which is borax. I have seen some puck with this added to help prevent the pH drop from acidic trichlor.)

[bcb1]

I've had good luck with the HTH pucks and the Sam's Club brand pucks - i guess they're all about the same. You're smart to keep your eye on your CYA level. There is a tremendous amount of disagreement on how much is too much -- some folks say 30-50ppm is ideal, and that has been the conventional wisdom for some time. My pool is about 80ppm, and I've never had a problem at all. I use a chlorine puck or two in a floater at all times...just in case...but I normally add chlorine by using wal-mart ultra bleach. I just like having a puck or two floating in the pool in case I forget to check the level for a couple days and it drops too low.

[chem geek]

Please refer to Ben's Best Guess CYA chart. The issue isn't whether your particular pool has never had a problem at 80 ppm (and what FC?), but whether ALL pools will be guaranteed to not get green algae if they maintain a certain FC at a given CYA level. That's what the chart is about. Your pool may not have nitrates or phosphates in them so you won't get algae because of that even if your FC is lower than the Min on the chart (for your CYA), but that doesn't mean that everyone's pool will be the same. In my early days (before I found this site and before I figured out some pool water chemistry), my pool got to over 100 ppm CYA with only 3 ppm of FC and didn't get algae, but I was using algaecide regularly and had the pool covered frequently.

Also, you can absolutely have rather high CYA (even close to 100 ppm) with relatively low FC (say, 3 ppm) and not get algae if you use a weekly dose of PolyQuat 60 algaecide, but that is more expensive. It does let you use Trichlor tablets in a floating or inline feeder instead of having to add chlorinating liquid or bleach every day. So there are options, but they have differing pros/cons.

There has not been one case, and I mean literally one case, of green algae in a pool following Ben's chart -- and that's with chlorine alone and no algaecide. There have been reports of the heartier mustard/yellow algae, but we figured out the higher level of chlorine needed to keep that away (essentially the Max column in Ben's Best Guess CYA chart or the 0.07 column in my chart (the 0.03 column is the minimum to prevent green algae and 0.05 is the typical column that is followed and is in between Ben's Min and Max columns).

One of these days I would love to create a tub or basin with equivalent pool water (i.e. with calcium chloride and sodium bicarbonate) and add nitrates and phosphates for a great algae bath and then see exactly how much chlorine it takes to just barely inhibit the algae (green and mustard/yellow) in their best growth conditions. That's an experiment that this industry should have done a long time ago, but never did. One guy did do an experiment, but didn't maintain FC levels and didn't ensure there was no ammonia in the algae extracted from its broth and he "proved" that CYA didn't matter (you can guess why -- the amount of monochloramine that's formed is independent of CYA and it kills algae). His study was funded by Olin Corp.

Richard

[CarlD]

I've had good luck with the HTH pucks and the Sam's Club brand pucks - i guess they're all about the same.

Unfortunately, that's not true. HTH is adding copper, which turns blonde hair green and stains liners, just so they can say "Dual Action!" on the label. It is an algaecide, but chlorine is more effective.

Unless you have a specific need for copper in your water (and it does happen) I would avoid Tri-Chlor pucks that are fortified with copper.

Tri-Chlor is tricky enough to use correctly--it adds CYA rapidly and drops pH rapidly as well. That doesn't mean you shouldn't use it--it just means you should watch your pH and CYA levels carefully.

Tri-Chlor is GREAT for people with new hard-surface pools that are still curing. Such pools will need CYA, and Tri-Chlor brings it up gradually enough to allow good control. Also, curing pools tend to drive pH 'WAY up--the acidity of Tri-Chlor helps control that as well.

But Tri-Chlor is sold as a full-time, all-you-ever-need chlorine solution, and it is NOT that. Only bleach/Liquid Chlorine and Salt-Water Generators qualify as that.

[Poconos]

My original post was before the forum crash. Probably 2 years ago at Sam's Club they had two types of tri-chlor pucks. Both same weight, same concentration, same listed ingredients. No mention of copper. I know that because I was aware of the copper addition at the time so I specifically looked at the label. One bucket $10 more than the other. The more expensive was tagged as 'all purpose' or something like that. Nothing more to say than just try and be aware.
Al

[PhantomAndy]

Without debating the right/wrong way to use Trichlor tablets, I would highly recommend the Leslie's store brand. They have a competitive price in store, and if you get on their mailing list, they always have a 10 or 20% off coupon that arrives around opening time.

Their Trichlor is 99%, with 1% inert - no fluf-n-stuff