Why does the pickup tube in the Pentair Acid Tank stop so far short of the bottom?

[Swimmer35]

Others have mentiond that the pickup tube in the Pentair Acid Tank stops far short of the bottom reducing the potential 4 gallon capacity to only 3.5 gallons and I see in mine that there is a little pickup "filter" at the end making it even worse. Does anybody know why this is?
Putting 2 gallons of muriatic acid in would result in less than 1:1 dilution. And 1:2.5 would be a substantial reduction in capacity. Of course I can put fractions of gallons in and will probably do that, but it's much less convenient.

Is it because the muriatic acid slowly sinks to the bottom and the concentration there is much higher, so Pentair doesn't want to pick up from there? If so, then when the tank is "empty" the 0.5 gallon at the bottom distorts the concentration of the refll.
It's clear they are doing it for a reason and I'd like to know why, so I can understand the effects.

 

[ajw22]

I don't think any of us here know for sure. But @Dirk will spin a good tale for you.

 

[JamesW]

Maybe to avoid picking up solids from the bottom.

Contact Pentair to ask them.

1-800-831-7133

https://www.pentair.com/en-us/education-support/contact-us/pool-spa-equipment-customer-service.html

https://partners.pentair.com/s/pool-consumer-product-support

 

[JamesW]

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[Dirk]

There is, in fact, a filter on the end of that tube, but in my tank, the filter touches the bottom. I have seen my tank virtually empty, perhaps a cup left on the bottom, if that. If your filter is not touching the bottom, then you can adjust it so it does. You'd have to disassemble the top of the tank from the bottom half and replace/extend the tube.

So there should be no large amount stuck in the tank. There is no conspiracy by Pentair. There's no diabolical, or practical reason, to keep a bunch of unusable acid in the tank. The feed tube has to have a filter and that filter takes up as much acid as possible. It's not going to be 100%, but it's pretty close. And as far as I know, the acid doesn't separate from the water, the 1:1 dilution remains so, throughout the liquid column, whether the tank is full or near-empty.

While I have loaded mine with four gallons, the liquid tops off in the IpH's throat, above the grate, which is above the white part of the tank. I don't think that causes any harm, but if you keep the level well below the grate, and below the seam, you only get about 3.5 gallons anyway. Pentair is being "generous" when they say it's a four-gallon tank, but technically it will hold four gallons. I suppose keeping the mixture below the seam is prudent, so really it's a 3.5 gallon tank.

Regarding the mix, whatever is left in the tank, be it a cup, or a couple inches, or half full, doesn't affect the refill mix, at all.

When I refill, I grab a gallon of 31% acid and mark its level, with a Sharpie, on the outside of the jug. I pour the acid into the IntellipH, then fill the jug with water to the Sharpie line.* Then pour that into the tank. That makes a perfect, and the recommended, 1:1 dilution. If the tank was near empty, I'll do that again, and get four gallons of 1:1. But if the tank was partially full (which it almost always is), what is in the tank is still 1:1. Adding any amount of acid, and an equal amount of water, results in 1:1. So I'm not sure what you're having trouble with, mix-wise.

I never want the tank to be fully drained, because I don't want it to run out when I'm not paying attention to it. So I throw in a couple gallons (of 1:1) whenever it fits. I've never felt that was inconvenient, since I only have to do that a few times a year. And I like that the tank only has, at most, 2 gallons of 31% in it, because if the IpH controller ever malfunctions, that's the most that could ever end up in my pool. It'd tank the pool's pH for a while, but would not result in any real damage or an unsafe body of water. I would never want to use a 15- or 30- gallon tank of acid, like some Stenner solutions. That's just asking for trouble. The "inconvenience" of a four gallon 1:1 tank is what keeps it safe.

* Pouring water into an empty acid jug, and/or pouring water into a tank of acid solution, is not the preferred procedure. You're always supposed to pour acid into water. But that's not practical for me. Trying to mix the acid into water, like in a bucket, and then pouring that into the IpH was much more prone to spillage, and making fumes, than the way I do it. I wear protective gear when I fill my tank. A full face shield and a breathing mask. It's the safest MO I've come up with. I have had splashes of acid-water come back at me while filling the tank, so I highly recommend a full-face shield.

That all said, you can avoid ALL of these issues by buying and using only 14% acid (sold at most big-box stores). That's a good dilution, and you never have to deal with mixing or diluting or whatever. Just pour in enough jugs to fill the tank and properly store the leftover (outdoors, somewhere safe).

 

[Dirk]

PS. Just to make sure: you do know that the throat of the IpH is designed to hold a one-gallon jug upside down in it, right? It's even got a "piercer" at the bottom of the throat. You're supposed to take the jug's cap off, but leave the seal. Then you lower the jug into the throat, up-side-down, and when it bottoms out the seal gets pierced and the jug empties. You can walk away while it does so, minimizing your exposure to splashes and fumes. It really is a smart design. And, again, if you use the 14% acid, refilling the tank is a breeze. You can go check your pump basket, or skimmer basket, or test your water as each jug "glug-glugs" into the IpH. That's about as convenient as adding pool acid gets.

WARNING: I have had that seal pop off while loading the jug into the throat, and the acid poured and splashed before I was ready for it. So you need to load that jug carefully, assuming the seal is going to pop, so that if it does, you won't get acid everywhere.

PPS. I love my IpH, and despite its bugs, if it stopped working today, I'd have another on its way to me tomorrow.

 

[Dirk]

Oh, and just because I can't help myself, I love to show off my cams. I have a PTZ "pad cam" that can look around my pool's equipment pad and monitor everything going on there. Here's the preset view of my IpH. I can see the level without it, through the side of the tank, but a strategically placed mirror (plastic, of course) makes it even easier to see. I can make it out on a cloudy day like today, or with the cam's infrared light at night. I can check my acid level anytime, from anywhere in the world.



I'm a little over half empty. Maybe I'll top it off today while I'm thinking about it...

 

[uraceulose]

I'm going to have to steal that mirror trick!!

 

[Dirk]

I'm going to have to steal that mirror trick!!

Ha, ha. I've got 'em all over my yard, and I've posted a few pics of them here (to some ridicule)! But it's like adding an extra cam for just the price of the mirror. I use mostly PTZ cams, and the mirrors extend what I can look at. Here's one that keeps an eye on the end of my pool's overflow pipe, so I can see if my auto-leveler system is malfunctioning. The pipe dumps into a drainage pit, that my "pool cam" can't look into... but the mirror can. I "sold" that idea to someone else here. Bicycle/motorcycle mirrors work well, because they're made for outdoors and they're adjustable.



The only thing I haven't solved yet is the rain can mess them up. I'm trying Rain-X with mixed results. This mirror has a little tin roof over it, which helps some.

Here's another trick. I wanted my "pad cam" to be able to see my filter's pressure gauge. I had first tried a mirror, but that didn't work well, gave me a reversed image, and looked like H. Then I realized I could just point the gauge at the cam! I used a 90° fitting and then added a cowling to keep the sun off of it (these cheap gauges tend to cloud up after just a couple years, so I'm experimenting to see if keeping it out of the sun helps with that).



And when I say "PTZ" I mean Z! This is the kind of zoom and resolution I can get when I need it:



I'm still working on the mirror for my flow meter. I don't have that quite right yet. It's a project for another day.

I'm using a PTZ cam over my pad, and it accepts presets. So I just type numbers on my laptop, 1, 2, 3, etc, and the cam will pan and zoom for views of the IntellipH, the SWG (I can read the label when I need to), the pump, etc. This last summer my cam spotted my malfunctioning SWG. Not sure how long that would have taken to notice otherwise.

Overindulge much? Sure. But after using it for even a short while, I became pretty dependent on it. Which is a warning of sorts... it's addictive... and I've got it bad. So beware, it's a slippery slope!

 

[Dirk]

Oops, sorry for the hijack @Swimmer35, I thought that was you commenting about the mirror. My bad. See, I really can't help myself!!

 

[uraceulose]

That is so awesome Dirk!