pour bleach in skimmer or directly in pool?

[Cherie]

I only add 1 qt of 10% (or 1.5 - 2 qt 6%) each evening (for now anyway). I have my 2-qt plastic pitcher marked for each half-quart with a black marker. I pour bleach to the 1st half-quart mark, fill the rest with pool water and slowly add it to the skimmer. Then repeat that process to reach my 1 qt of 10%. Which means, it takes me about two minutes to pour bleach, dilute with pool water, pour slowly into skimmer... and I'm done!

I guess it would depend on how much bleach you have to add each evening. But even at three or four quarts, it would still be quick and easy to dilute each half-quart with pool water in a 2-qt pitcher and add it to the skimmer.

 

[chem geek]

Dry acid products were diluted in a ratio of 1lb. per 5 gallon bucket of water, mixed for several minutes and emptied along the deep end of the pool.

One pound of dry acid (93.2% sodium biulfate) is equivalent to 34 fluid ounces of full-strength Muriatic Acid (31.45% hydrochloric acid). So the dilution is around 19:1 so the pH is around 0.3 which is very low.

If one pours a concentrated chemical near the side of a pool and it doesn't flow downward into a return flow, then it can concentrate near the side and mostly down towards the bottom as both acid and chlorine are denser than water until mixed. I'm not saying that pouring slowly into a return flow (arm outstretched to be away from the wall, if possible) is perfect, but it's definitely better than pouring generally into the bulk pool water not into a return flow.

We'll have to monitor what happens to people's pools over time to see if there is any sort of trend. I know that several Pool Builders (PBs) swear that using bleach in vinyl pools destroys them (which makes no sense compared to other chlorine sources), having the vinyl get paper thin and weak, but we've also had reports of Cal-Hypo ruining vinyl bottoms and Trichlor floating feeders parking near a side where the acidity causes problems. When we looked at reports from many vinyl pool users, it looked like UV from sunlight led to fading and that repeated addition of chemicals, especially in one area not into a return flow, could lead to some issues in that area, regardless of chlorine type and especially for acid addition.

It's been quite a few years since the "pour slowly into a return flow" advice so we'll carefully monitor what happens over many pools to see if the recommendation should change. By the way, I'm much less concerned about chlorine in the skimmer (except Trichlor) than acid.

Richard

 

[johnsjets]

One pound of dry acid (93.2% sodium biulfate) is equivalent to 34 fluid ounces of full-strength Muriatic Acid (31.45% hydrochloric acid). So the dilution is around 19:1 so the pH is around 0.3 which is very low.

It certainly looks like the dumping of the acid at the deep end might be the smoking gun. As I had stated previously, the dumping of the chemicals directly into the pool was under the advisement of a previous pool maintenance person.
I have since learned that such a practice can certainly affect the life of the liner. The installer of my current liner said there is nothing in pool maintenance that doesn't carry some risk. He advised that the using the skimmer method of chemical introduction into a vinyl lined pool, carries by far the least $ damage you can do. Even with the careful application of chemical solutions directly into the pool, he believes that you will experience less liner life as opposed to the skimmer method...and this is from a person who derives a partial livelihood from the installation of new liners, lol.
The addition of dry acids at the skimmer was also under his advisement. No more than 1/2lb. at a time poured into a filter sock while running the filter continuously until thoroughly dissolved. So far things have been just about perfect, with the liner holding up nicely. I guess I'll really know more in another five years or so. Hopefully, I'll still be here to report back to the group.

 

[Cherie]

Update on our pool. We've been adding the chlorine through the skimmer for five years now and the liner is holding up wonderfully. I don't pour the MA into the skimmer, but rather, at the strongest return flow and as I slowly pour it in, I stir the water a little and watch it disperse even faster.

The dual-speed pump we installed four years ago is working the same as it was, new, four years ago. We leave it on low all the time, even through the winter. In fact, we even leave it on while the Aquabot Turbo is running, although, we have no bottom drain, so that would make a difference with the cleaner.

The only problem we've had, other than sun-bleaching, is that the caps are all sun rotted and need to be replaced. Thanks to this site, our pool has been virtually care-free since installation. Thanks, TFP!

 

[DaveNC]

I read posts by some people talking about pouring the bleach into the return stream at the deep end (like the one above). My pool has three return eyes, and they are all in the shallow end. The single skimmer is at the deep end. Does that make using the return stream method riskier to my liner than the skimmer method? Or is it ok to pour chemicals into the return streams at the shallow end?

Dave

 

[chem geek]

If you are pouring a larger quantity, you can split the dosing to two or three returns. That's likely to distribute the chlorine well. If you are dosing just a pint or two, then adding it over one return should be fine.

 

[DaveNC]

Thanks for clearing that up.

Dave

 

[Syrr]

I take a minority position on this point. For me, it is most convenient (and I truly believe it to be totally harmless) to pour my bleach (liquid chlorine) directly into the skimmer. It's a matter of convenience for me and I have yet to read anything definitve to "prove" the harm.

That said, I must admit it has become a minority position.....most folks prefer the returns.

Liquid I pour into the pool, but have been pouring granular into the pool skimmer. It dissolves overnight with the pump running. Thoughts or recommendations welcome.