Variable-speed pump

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I'll try and watch the surface next time the cover is off in the daytime, and let you know how the surface flow looks with the VF running at 23 GPM.

Related to the Sunken Treasure, I do find my cover deteriorates. I do use chlorine floaters. My covers (12 mil) currently last about three years before they need replacement, it appears that the water side of the bubbles go first.

While the flow rate is lower, I'm pumping more than double the number of hours right now. So, I'm not sure about the higher chlorine concentration on average over the whole day. The chlorine concentration would certainly be the highest when the pump was off, and there was no flow.

There is another short thread about the Sunken Treasure here:
sinking-chlorinator-input-wanted-t24633.html
There were concerns about plaster mentioned.

I wrote an email to the safensavepoolchemist website, and received an immediate response from Kim, the inventor. It still sounds pretty interesting, and she has a US patent on it. Wrote back asking about plaster damage, from tabs directly on plaster, or just off the bottom in Sunken Treasure, here is what Kim replied:

Hi Jeff,

Yes, if you put the 3-inch tab(s) directly on the plaster, chlorine will burn (so-called chlorine burn) the plaster which cannot be removed (like when wood is burned, you won't be able to reverse it back to wood). On the other hand, the Sunken Treasure is well-designed - it rarely stands still in one position and the plaster is protected by Sunken Treasure wall materials. The chlorine tab never comes in contact with the plaster, nor is it possible for the tab to get close enough to the plaster to cause damage. With over 15 years of the Sunken Treasure on the market, no one has ever complained about stains on the plaster due to the Sunken Treasure itself.

Kim
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Jeff
 
I have another thought on the Sunken Treasure. If it really does save you from using less chlorine tabs, then pool stores might be reluctant to carry it.

The pool stores might make a very few bucks on the Sunken Treasure, but would then sell less chlorine tabs!

Jeff
 
It is true. Our products (when our company was named Aquasave, Inc) were in Home Depot stores in Arizona, Los Angeles, San Diego, and Las Vegas, as well as in local (AZ) Fry's Food, Safeway, and Ace Hardware stores in the early 90's. Purchasing agents come and go, and they soon realized that our products were saving pool owners too much money. Aquasave users (the Sunken Treasure hadn't come along yet) were no longer buying liquid chlorine, shock, algaecide, pH balancers, etc. Bigwigs like HTH and Pace weren't happy. I'll let you figure out the rest.

Anyway, big box stores like Walmart and pool supply stores don't want to carry our products. When a small bucket of tabs cost $57 at Walmart, they don't want pool owners buying FEWER tablets. And because the Sunken Treasure chlorinates your pool from the bottom-up, shock is no longer needed. Your floater-chlorinated pool has little to no chlorine at the bottom. That's why you have to regularly use shock. Don't believe me? Dive down to the bottom of your pool with your test kit (your thumbs plugging it until you fill it up with water from the bottom) and see what kind of chlorine readings you get.

It really is a no-brainer product. An elegant solution on so many levels. It only costs $20 plus shipping (which isn't much more than a cheap floater), but you will realize immediate savings in tablets and shock, you will enjoy a healthier swim, and the Sunken Treasure will last 5 to 10 times longer than a floater because it is made with a superior polymer and isn't getting damaged by the sun.

We really only started advertising for the Sunken Treasure in 2010 on local radio. That's probably why few people have heard of it.

Thanks.
 
It's bad enough to have a floating chlorinator park itself near some stainless steel bars in my pool 7 years ago and rust out the mounts, but having the Trichlor tabs sit near the bottom of the pool having the Trichlor acidity concentrate there isn't great either and for vinyl pools in particular the acidity can be a serious problem. The Sunken Treasure even has slots in the bottom half of the unit which is very close to the pool bottom. Trichlor anywhere there is poor circulation is going to be a problem if that's near a pool wall or floor. Even in the middle of the pool on the surface is a problem for the pool cover. It would have been better to have it be able to be higher in the pool (or to be an inline chlorinator).

As for a floater, it is not true that most of the chlorine dissipates into the air. This completely depends on the amount of circulation and whether or not you use a pool cover. If circulation is poor then having the chlorine concentrate at the pool's surface will have it break down faster in sunlight since there is less CYA shielding at the surface (though most of the chlorine is still bound to CYA so still gets that benefit).

If there is poor bottom circulation, then Sunken Treasure won't have a lot of chlorine used up since it won't get distributed throughout the pool, but what you save in less chlorine getting released you lose in algae being able to grow closer to the surface and on walls.

Of course, continued use of Trichlor tabs/pucks can rapidly increase the CYA level in the pool. For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases CYA by 6 ppm. So even with a low 1 ppm FC per day chlorine usage, that's over 100 ppm CYA added in 6 months if there is no water dilution.
 
Thank you guys for your support. However for reasons of circulation your argument would seem to favor a conventional 'tricity-hog' over the VF....

....especially in a pool not using a vigorous sweep like the Polaris

Slightly OT but my local Bill's Pool and Spa advises that even if I use tabs, replenishing regularly (maybe once a week), I should nonetheless toss in a dash of chlorinator every day. But then why use the tabs at all

Also they maintain--contrary to Pool School and other cherished links--the proposition that a high CYA diminishes Cl concentration is "very questionable" and so if I have a high CYA but difficulty maintaining a high Cl level I might look for other reasons

Their suggestions seems contradictory
 
dalehileman,

I guess the argument about pool flows, is how much circulation is enough? Both how much flow in GPM, and how many hours a day.

I was running my 1 HP single speed pump about six hours a day, and using about 9.6 kwh a day (testing with new VF at various GPM, and reading filter pressures, I'm guessing about 50 GPM, or less). My new Intelliflo VF is running at 23 GPM, for 14.5 hours, for about 3.9 kwh. So I'm running my pump for 8.5 more hours during the day, and actually flowing a bit more water.

So, what's better for the pool water and chemistry, water blasting through at 50 GPM for six hours a day? Or a much slower, but still noticeable flow at 23 GPM for 14.5 hours?

I don't have all the answers, but it's an interesting question.

Jeff
 
ride525 said:
So, what's better for the pool water and chemistry, water blasting through at 50 GPM for six hours a day? Or a much slower, but still noticeable flow at 23 GPM for 14.5 hours?
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The most important factor is the total amount of water moved through the filter. Those two don't move the same amount of water. 50 GPM for six hours is 18,000 gallons through the filter. 23 GPM for 14.5 hours is 20,010 gallons through the filter. In most cases, moving more water through the filter is going to be better, regardless of flow rate. (There is a limit to that, once you have moved "enough" water through the filter, additional water beyond that really doesn't help/matter.)

I suspect you were actually intending to compare the pump running at different speeds but moving the same total amount of water. In that case, the effects are very very similar. The only significant effect, which has nothing to do with chemistry, is that the slower pump will use less total electricity to move the same total amount of water. There are a variety of secondary issues that can cause differences, but they are mostly very minor. One somewhat significant difference, at low enough pump speed the skimmer(s) may stop working effectively. This can be a problem/annoyance, as more debris will sink to the bottom.

There are various other very minor effects that you could measure with lab equipment, but they almost never make a significant difference. For example the total chlorine used will vary a little depending on the pump running during peak sunlight or not. Just slightly more chlorine will be used if the pump is running during peak sunlight if your don't have a SWG, while just slightly less chlorine will be used if the pump is running during peak sunlight if you do have a SWG. But most people would be hard pressed to be able to detect that difference.
 
Again thank you guys

"One somewhat significant difference, at low enough pump speed the skimmer(s) may stop working effectively. This can be a problem/annoyance, as more debris will sink to the bottom."

My main concern is the flotsam as I have indicated. While my Polaris will take care of the bottom, I'm afraid that excessive flotsam on top might indeed prove a problem. Pertinent to this matter, however, was an earlier comment that the flotsam might be moved along by occasionally switching to a higher speed. So what's entailed in the speed change

Specifically is it easy: Would the capability require a whole lot more plumbing or complex wiring; or is the feature built in: for instance, where a switch is provided on the pump itself
 

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Jason,

Yes, I knew there a difference in the amount of water flowing in my two examples. From the approximately six hours I was flowing with my old pump before, and the 14.5 hours I am now, I mentioned I was actually flowing more water now. (It's just over 10% more turnover now.) This was just a before and after example that I had.

But I guess the question is, what's better? Having the pool water still for 18 hours? Or having it still for less than 10 hours at night?

My skimmer seems to skim ok at the lower flow. So it's actually skimming a much larger percentage of the day.

I was just wondering if algae formation, or chlorine usage, would benefit from either flow.
EDIT: I just looked at Pentair's claims for Intelliflo:
And when water moves slower for longer periods, good things happen. It helps reduce the occurrence of algae that forms more easily when water is allowed to rest for long periods. It makes your filter more effective, because it has more time to strip particles from the water, plus small particles aren’t forced through the filter media under unnecessarily high pressure. Automatic chemical dispensers and chlorinators are also more effective when water keeps moving.
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Thanks,

Jeff
 
dalehileman, from a water chemistry point of view, it doesn't matter if the debris is on the surface of the pool or in the skimmer or on the bottom of the pool. The significant issue is if it sits on the surface of the water long enough to sink, then you need to clean it up. Yes, the Polaris will pick it up, but that means more cleaning out the Polaris debris bag. These are all minor effects, but more frequent cleaning of the debris bag is something people notice.


ride525, I've said this a number of times. The number of hours the water sits still is a very minor effect that hardly anyone will notice a difference from. Yes, you might be just able to notice some difference, but it really doesn't matter. On the other hand, the higher total flow rate might matter a lot, or it might not make any difference. That depends on how much total flow your pool needs. If 18,000 gallons wasn't enough, then 20,010 gallons could help a lot. If 18,000 was enough, then 20,010 won't be any better.
 
dalehileman said:
Another factor you guys might address: While the VF probably provides a significant saving in kWh, if it runs for, say, twice as long, then it presumably it will wear out that much faster. So now the cost of replacing it might figure in to one's decision
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Well, the motor, while pumping a longer TIME, it's spinning slower. In my case, well less than 1/2 the speed of my old motor. Pentair has a lot of claims about their Intelliflo motors:
Dramatically longer life.
Permanent magnet motors produce far less heat and vibration than traditional induction motors. The result is not only less stress and wear on pump components, but on other equipment, too. IntelliFlo’s motor is also a Totally Enclosed Fan Cooled (TEFC) design that provides exceptional protection from the elements. You can expect dramatically longer life for an even greater return on your investment.
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Jason, thanks for your thoughts on my pool run times. I have had the VF running for less than a week, and plan to adjust run times. As you point out, perhaps 20,000 gallons might be more than enough.

Thanks,
Jeff
 
dalehileman said:
Still like to learn about means for selecting VF speed
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You don't actually choose the speed on the VF. (Well, while in testing in manual mode, you can choose a RPM speed, or a GPM flow rate.)

But in more normal Filter mode, you tell the VF, the size of pool you want to turn over, and how many turnovers per day. Then you program from one to four program times. You can also program "Features" numbered 3 - 9 if you want different flow rates at different times of the day. The VF then calculates the needed GPM flow to achieve the turnovers you programmed, for the pool size you specified.

Jeff
 
jeff thank you for that report. I assume then the electronics is in a separate box one mounts on the wall

From what you've said I assume then there are two modes, filtering and manual. Does filtering not take place in manual mode and if that's the case doesn't a changeover entail some plumbing alterations

As my existing pump is on a mechanical timer I had hoped I might make a quick substitution. To save me the trouble (as Amazon ads are so sketchy), do you know whether one might procure a simpler model, maybe with speed control but none of the rest of the electronics

Thank you again for your inputs
 
dalehileman said:
jeff thank you for that report. I assume then the electronics is in a separate box one mounts on the wall

From what you've said I assume then there are two modes, filtering and manual. Does filtering not take place in manual mode and if that's the case doesn't a changeover entail some plumbing alterations

As my existing pump is on a mechanical timer I had hoped I might make a quick substitution. To save me the trouble (as Amazon ads are so sketchy), do you know whether one might procure a simpler model, maybe with speed control but none of the rest of the electronics

Thank you again for your inputs
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The electronics are not in a separate box. They are built into the pump. You might want to check out the VF info brochure here: http://www.pentairpool.com/pool-owner/p ... ump-77.htm

The intelliflo runs on 230 volts. So keep that in mind, if your current pump is 120 volts. My existing pump was on a timer too (electronic, but same idea). I just set the timer to be on all the time. So, my old timer does NOT control the Intelliflo VF, the controller is built into the pump itself. There are three models of the Intelliflo pumps, the VS-3050 (most simple), the VS-3050+SVRS, and the VF. You can get more info on them out on the Pentair website. My understanding is you can run the VS-3050 with a mechanical timer, turning it off and on. You then have to manually make any speed adjustments you want, such as for vacuuming or backwash.

The VF has lots of modes. There is Filter mode, where the pump does the calculations I explained in earlier post. The Manual mode also could be used to filter, but is mainly used for testing pump. There is a Backwash mode, and Vacuum mode. Check out the Pentair info for more.

My VF install was relatively simple, although the Intelliflo's have 2" connections, and my old pump had 1.5" connections. Had to connect pump intake and out with new 2", and adapt to my old 1.5" plumbing for the new 2" connections. Also, my old timer and pump were 230 volts, so I just disconnected old pump, and had to reconnect. I set the old timer to always be on.

Hope this helps you. There is a lot of good info at the Pentair Intelliflo website. Brochures and Manuals both.

Jeff
 
"Some, like the VS, may require a separate controller."

jeff thank you again for that report. A good and dear friend and crew had most kindly volunteered to replace my pump with a VF and the idea looks promising but there are yet a few critical factors. One thing that bothers me is the digital aspect as the pumping station isn't the best environment for that sort of thing and I don't think all that programming and software should be necessary. I had hoped the VF was available without all that frippery, maybe having only a switch to change its speed

But from what you and others report it appears we don't have much choice,, we might have to accept it in that form, while the idea of microelectronics in the Mojave Desert, hot sun beating down ten hours a day on a metallic housing,, saturated humidity to boot, just positively appalls me
 

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