Calcium hypo tabs

I would be careful of Calhypo anything. Once your CH gets up high enough, which could be sooner rather than later if your fill has high CH, you will have scaling. Have you looked into a Salt Water Chlorine Generator (SWG) ?

Also, it would be helpful if you added your pool and equipment details to Your Signature.
 
Cal Hypo tabs are generally used in sewage sanitation and don't stay "solid" for long. Folks report them turning into a gooey mess.

Cal Hypo tabs put in an inline chlorinator can have an explosive component that I have no interest in learning more about.

In short, don't use them.
 
Dave, Thanks for the information. I am searching for an alternative to the stabilized chlorine. One of the major pool chemical companies has a non stabilized cal hypo tab that they say is designed for the skimmer and I have talked with their rep and have been told it works good in the skimmer. My pool supply store has no experience with them.

I have kept my pool running all year with adding the granular calcium hypochlorite on a daily basis or as needed. Pool chemistry is good now.

18,000 gal vinyl pool hayward pump and filter.
 
What do you mean by "good?" What is your CH level?

I've done a little research on Calhypo tabs. Accutab makes 3" tablets that do stay solid.

They state they are 68% active chlorine, so using PoolMath's 65% setting, If the tablets are 8 oz, per your 18,000 gallons, each tablet would add a little more than:

FC - 2.1 ppm (only 70% of trichlor's FC per tablet)
CH - 1.5 ppm

Over the course of a season that could really add up. A typical 25 lb bucket give a little more than:

FC - 107
CH - 76


The same bucket of Trichlor would give:

FC - 152
CYA - 92

(You would need to add 64 lbs of Borax or 32 lbs of Washing soda over the course of the season to to make up for the acidity of the trichlor tablets.)


Also keep in mind, most users will need more than one bucket for 90-days of use. So in the end Calhypo tablets have less FC than trichlor but do not have the problems of rising CYA and pH going down.

It all boils down to your current CH level, your seasonal rainfall and your fill water CH. You may also want to factor in the cost of CH test reagents. They are one of the more costly reagents to get per oz.

On the other hand, if you don't want to have to worry about feeding tablets or pouring liquid chlorine in every day or two, again I advise you to look into Salt Water Chlorine generators. They can be had for as little as $150 plus the cost of salt, the majority of which is a one-time purchase. If you do look into the cheaper Intex models, find one without anything extra like Copper or Ozone.
 
Dave / Jesse, thanks for all the info. My pool chemistry tonight was Cl 3, Ph 7.4, Acid demand 110 CYA 40. I have not tested CH so I do not know. Tonight I have brushed the pool, removed the lights from their niche and brushed, super chlorinated and added preventive algaecide. Based on all the info provided I have decided to continue Trichlor for my away (i travel) periods and monitor CYA regularly. Will use sodium hypo or cal hypo for daily maintenance. I am not going to put it on auto pilot ever again. Probably high CYA was the reason for the yellow algae last season. Have not seen any this year but not taking any chances.
 

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It must have a lower flow rate around the tablet(s). Dialing it in just right could be challenging using a standard feeder, but it's probably doable with a good valve and the right plumbing.

As for the explosion risk, I noticed the Accutabs are tinted blue which helps but certainly doesn't make it idiot proof. I wonder what they've devised to stop people from putting Trichlor tablets in the Accutab feeder. The tablets seem to be the same form factor.
 
I've had CYA issues in the past as well and had to drain most of my 55k gal pool to get it back under control.

Since my drain and refill Ive been using this stuff called Refresh. It's granular 73% cal-hypo without stabilizer sold in 25lb buckets.

The pros are it is a strong chlorine source - albeit it's not without its side effects. Too much of this stuff and you will eventually have scaling issues caused by too much calcium. My CH levels are through the roof, but I haven't experienced any problems with how the water looks.

I buy the stuff locally from poolzoom.com here in San Antonio. You can order some via the website.
http://www.poolzoom.com/refresh-plus-25-bucket-73.html

I have purchased a SWG but haven't got around to installing it yet.
Good luck
 
I had a nice discussion with Accutab. In a nutshell, I would not consider them as a viable source for chlorine FOR RESIDENTIAL POOLS....their dispensers are not erosion type dispensers like the ones for tri-chlor and are much more expensive and typically will require some type of sophisticated timer to function properly.

Briefly, the tri-chlor tabs are immersed in water and the water passing over and around them slowly, slowly dissolves the tab.

Cal-hypo feeders DO NOT immerse the tabs in water. Instead, the water is brought in so it only moistens the bottom half of the bottom tab....about 1/2 "

This bottom tab then dissolves and the next tab moves down into the feeder where it is exposed to that pool water passing ONLY across the bottom of the lowest tab.

I probably have some details incorrect but the major point is Cal Hypo tabs have some great applications but a residential swimming pool is not one of them unless you want to spend some significant money for a pretty sophisticated system.

They simply will not work well in a tri-chlor feeder.
 
You know, my bet is you could toss maybe a couple in the skimmer and, pump running, they would dissolve quickly and be just fine.

I just don't need the extra hassle of worrying about them when they don't dissolve.......I don't think you can successfully take them out.

As always. Clorox is our good friend!!
 
I work with accutabs quite a bit on our commercial pools. Would defiantly work in a pinch in the skimmer but as someone else stated they are not designed to be fully submerged, they will turn to mush and dissolve quickly. The lids on most the accutabs ppg feeders are clear so when they are all stained yellow you know someone put trichlor in. I'm a bit partial to ozone. Can really decrease your demand for chlorine, and along with it the byproduct such as cya and calcium. works best with a vs pump on low speed so it can run 24hrs
 
I'm a bit partial to ozone. Can really decrease your demand for chlorine, and along with it the byproduct such as cya and calcium. works best with a vs pump on low speed so it can run 24hrs
Well you are in the minority here as they do not make sense in residential outdoor pools. In fact they are more likely increase the chlorine demand when the swim load is low. Plus they leave no residual sanitizer the bulk the water leaving a person at risk of person to person transmission.
 

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