Stenner Econ LD for MA

[AllenA]

Hi All,
I'm looking into Stenner pumps for MA and would like to get feedback regarding my analysis. I have not found other members mentioning using the Econ LD in the forums.

I run my Pentair VS pump at low rpm 24/7 all year along with an SWCG at low settings. My acid demand is up to 1 gal per week and becomes negligible in winter (live in AZ, so pool is not winterized). I read several of you use a timer with the classic series or Econ T while others use ORP systems. I prefer small constant all day dosing.

If the MA is mixed with water 1:1, my pool's demand of the diluted solution would look like this:
- Summer: up to 2 Gal per Week => 256 oz / wk => 36 oz / day => 1.5 oz / hr
- Winter: not sure (maybe less) 1/8 gal per week => 16 oz / wk => 2.3 oz / day => 0.1 oz / hr.

Seems to me that the Econ LD would be the obvious choice for what I want to achieve and covers my range of demand for the mixed solution:

Stenner peristaltic metering pumps Econ LD low volume dosing 50:1 turndown

Stenner peristaltic metering pumps Econ LD compact, variable speed, precise accurate low volume metering with 50:1 turndown

stenner.com

E10LHM flow rate: 0.04 - 2.4 oz / hr

Other pumps have larger dosing or very expensive such as the S model @ ~1k:

Stenner peristaltic metering pumps every Stenner type on one chart

The pumps at a glance chart displays every type of Stenner pump and their key features, flow rate outputs and operating pressure maximums

stenner.com

The only thing I don't like about it is that it does not have an input for flow. It would have been good to be able to prevent it from producing in the case that there is no flow.

Any comments are appreciated.
Allen

 

[jonpcar]

Hi Allen...I’m working on some Stenner “stuff” at the moment and saw your post. I am NOT an expert on Stenner pumps but I do have a couple of them and here is some input.

Diluting: Depending on your muriatic acid concentration % to start with (Home Depot sells both 32% and 15%...the higher concentration is a “much better deal”), my pool’s current needs may be similar to yours: I am dosing about 10oz of the 32% per day to maintain a ph of about 7.7, but I am still experimenting and taking data. I have to admit to years of “winging it” with the pH so I am trying to be more systematic this year, I installed the acid Stenner pump just last year. I have a five gallon tank and I dislike working with the MA, so I will avoid diluting it...in an attempt to fill it only every couple months or so. Unlike liquid chlorine, I don’t believe there are any issues with storing MA for long periods of time and/or in heat.

Both of my Stenner pumps are Classic, single head, fixed. They draw 180 watts each, more than my pool pump draws when I am skimming. I wouldn’t want to run them for long times and, in fact, one (maybe both) overheats and shuts off if run for about 30+ minutes in the heat of the summer. Your proposed model is very different...it doesn’t give current for 120v but it is probably roughly 2x that of the 230v.. .34amps which is about 40watts. Not bad...but the operating temperature is listed as max 105 degrees Fahrenheit...is it going to be outside? That could be a problem.

There are lots of ways to ensure that your pump is running/water is flowing in order to turn on your Stenner. Here is one I recently came across by one of the other forum members

Planning to add CircuPool RJ-60Plus

Looking to purchase the CircuPool RJ-60 Plus for my pool. Just want to make sure I'll be setting it up correctly. I understand the plumbing aspects and the need for straight pipe, but am still confused about the electrical aspect. I have a VSP with its own onboard timer and is directly powered...

www.troublefreepool.com

Is there a particular reason you want to inject the acid so slowly? There are good reasons with the chlorine, but I have not heard of any real advantages for the acid besides the impact that significant changes in pH have for those that use ORP (very few). Since you run your pump 24/7, no matter what you do it will mix fairly quickly. Have you considered dosing a few times a day (3-4) to attain something similar to your goal?

@Stenner Tech Support might be able to help you determine if your choice of pump is appropriate for what you want to accomplish...in particular running 100% of the time in an outdoor (Phoenix) environment. Good luck.

 

[AllenA]

Hey jonpcar,
Thanks for your input and I see you're in Gilbert. Pretty cool and good to meet you.
So, I surely use the 34.5%. The other stuff is not worth it. And yes, I also read that MA does not degrade which is good. I was planning on either buying the Stenner tank (15 gal) or even an after market chemical tank for 2 reasons: 1) cheaper 2) I can get a different shape which will help me position the tank in a more suitable spot. Still thinking about it...

Now that is very interesting about the operating temperature. I would have never though and did not notice it. Yes, it will be outside, but no direct sun. Still, it will get hot for sure. Aren't all those pumps however really the same internally?
Here is what I assumed about those pumps without looking into all the details. And please note that all the following are my assumptions without ever hearing about them until last week so I may be totally off. But, several are the same size, yet are rated for different flow rates. The mechanical parts seem to be the same. So, I imagine that a full 360 deg. rotation will always pump the same amount of fluid regardless of the pump. They would just be internally programmed differently for different needs and by that it must be internal timers that start and stop them at different intervals. If my assumption is correct, it means that to be able to pump out such small amounts, the motor should only run when needed. So, let's assume that a 360 deg. rotation pumps out 1 oz (this must be documented somewhere but can't find it now). In the case of the LD, it would then rotate 1/0.04 = 25th of a rotation to pump out the 0.04 oz. I imagine that it would use negligible electricity while idle and also no strain and no overheating. If I were to make it pump for say 5 minutes to catch up to my complete daily dose, the chances of overheating are more likely. Does that make sense?

That said, in the end, I assume it is all still time based, you just don't have to deal with an external timer or the restriction of the Econ T's 24 intervals. The LD states 50:1 turndown for it's potentiometer which I imagine means that you have 50 different internal timers or intervals to chose from. I would expect the unit to be "dormant" and consume very minimal energy for just the timer while the motor does not turn.

Over the Econ T, I feel that it would be simpler. I won't have to program a weekly schedule. And then adjust all 7 days of the weekly schedule to meet the changes in demand. I imagine that if you set the Econ T to run for 2 hour per day and you need more, you'll have to change all 7 days on the Econ T's schedule or only 1 day and run with an imbalance between the days. So, instead of thinking about increasing/decreasing time, you would think about percentage of the max dose which I feel is much simpler. Dial up or down. Now again, all this with a grain of salt and big assumption but I will call them to confirm on and post it back here:
- Operating Temperature
- Energy Consumption while running / idle
- My assumptions on how it operates

Also, injecting slowly seems to be the right thing to do to follow my pump /SWCG schedule. All ducks in a row
All that said, should it not work due to wrong assumptions or operating temperature restrictions, I will go with a fall back plan.

I did notice threads on DIY flow sensors but still would have expected or maybe hoped that the pump would have it as a safety feature. I'll read those threads more closely and see if I want to go ahead with it. I've been DIYing too much lately... My pump has been very reliable so the chances of failure are small, and with such small dosing, I would hope to catch it in time, but still for peace of mind, it would be good to have.

Allen

 

[AllenA]

hmmm..., ok so even before contacting them, i checked now during my quiet evening and can see different models can have different motors so my first mistake (they are not all alike) and they surely can have different operating temps.

Here is something interesting though from the installation manual:

https://stenner.com/wp-content/uploads/2014/12/IMELD.pdf

And, 40 C = 104 F which is what the max operating temp is listed as on the pump's page. But the tubes should all be the same, so... ?!
Now, in the classic's manual, it states that the pump itself can overheat if operated at 125 F+ but there is no mention of the liquid's temperature and likewise, no overheating statement in the LD manual. Only temperature mentioned is about the liquid's. An oversight?

One thing to note is that both the S and the LD are brushless motors .

I'll try and call them tomorrow to find out more.

 

[jonpcar]

Allen, I don't think all your assumptions are correct. The classic Stenner pumps are similar, but I think they have introduced entire new families of pumps that are totally different from that series. I don't think you will have to worry about power (its much lower than the classic series), but you might have to worry about overheating when it runs continuously. I use a sprinkler timer to inject my liquids once a day. I will be changing my chlorine injection methodology but I probably wont be changing the acid methodology unless I end up getting a pH monitor.

I actually have increased the size of my Stenner tubes to allow me to inject faster. You might be overthinking the need to gradually dose the acid over an entire day but if you find one that works, go for it. Hopefully the stenner tech (who is new to the boards) will chime in....or OTHERS?

 

[Stenner Tech Support]

Good morning,

In our Classic Series Pumps they are very much the same mechanically. When you see our output charts you'll notice that the gear ratio/tube size determine the output. So a 45 with a #1 pump tube will pump 3 GPD and an 85 with a #1 pump tube will have an output of 5 GPD. See the full charts at stenner.com - As far as which Econ series you think would be best, it all depends on what you are trying to achieve. Obviously this thread is discussing the use of a pump for pH adjustment. Both the Econ T and Econ LD will work but there are a few determining factors. How will the pump be powered? How long do you want it to run? Will it be continuous duty? Of course the temperature in a very hot climate does come into play - the pumps are all designed to shut off at certain temperatures to prevent the chance of an accidental fire. I hope I've answered a few of your questions but as always I expect there to be more. Feel free to call in to our tech department at 800-683-2378 - we look forward to helping.

Thanks

 

[AllenA]

Hi jonpcar, you are correct. And I did call today to get some of my assumptions clarified.
Hi Stenner Support. Thank you for your input.

I got the below questions answered today regarding the Econ LD, specifically, the E10LHM w/ flow rate: 0.04 - 2.4 oz / hr. Here are the details:

- Operating Temperature
--- Thermal turn off switch is similar as other pumps. Means that it will shut down at 125 F just like the others.

Why does the manual state that the max fluid temp is 40 C? Will it degrade the tubes faster?
--- Tubes can get gummy when liquid is too hot.
--- This applies to any pump using the same tube (Sanoprene).

Many in AZ and hot climates are using Stenner Pumps. Wouldn't the tubes of the other pumps also be subjected to the same temp restrictions?
--- Yes.

What is happening when it is idle?
--- It is never idle, there are no internal timers. Motor runs constantly.

How can it pump out only 0.04 oz / hr?
--- You are fine tuning the RPMs of the motor with the potentiometer. Motor is running constantly at extremely small speeds.

Can it be controlled using a flow switch?
--- Not directly. Must go DIY directly to pump or put something in between.

@Stenner Tech Support, please let us know if I misunderstood any of the answers.

As for my particular use case, phone tech support (thank you BTW) believes that it makes total sense to use it for my application of MA running all day. I am not thrilled with the idea that the motor is constantly running even at such low speeds. I cannot even imagine how it can "run" at such small speeds to only pump out 0.04 oz / hr. Maybe I am still missing something here but I did ask the question 2 times and it seems that the motor will be running the whole time so no internal ON/OFF to just output the small amounts / hr. I am concerned with the fact that the pump will run continuously all day. However, I am no longer concerned with the operating temp max as it would run just like any other of their pumps and since others are using them in AZ then it should work for me. I guess there is no way to find out what will happen exactly until I try it first hand. I will give it a shot and order one and post additional information here to let the community know how it goes once installed and running.

Thanks again jonpcar for indulging with my assumption! Have a great summer to you and TFP!
Allen

 

[jonpcar]

Allen...others may chime in here because I am making an assumption...I have never seen anyone on these boards run their Stenner pumps for pool chlorine or acid 100% of the time. Everyone runs it for shorter bursts of time...once a day or multiple different times per day. So you won’t get any data from these boards that support an opinion that the stenner pumps can run all day, outdoors, in the hot Arizona temps without hitting their thermal limits and stopping. You might get that opinion from elsewhere because Stenner pumps are used outside our usage model.

You would be an icebreaker...but I am still failing to see a useful purpose for this experiment...sorry.

 

[AllenA]

Hey jonpcar,
If such a pump which dumps only what you need hourly or even per minute, and self managed "somehow" to only run when needed and therefore never overheats existed, would you not get it over the one that you can only control daily? Or the one that needs an additional external trigger? I would. For me, such precision is useful and can be more beneficial and simpler to manage. I am trying to avoid an external timer or fussing with schedules. Simpler setup and maintenance. I know that daily dosing is enough but also weekly dosing is enough. Would you getting an even bigger tube for MA and run it once per week? Or once every 2 or 3 days? I just prefer such an almost constant setup.

As for overheating, i surely don't want the unit to overheat. But how could it? I am still puzzled by this. It will pump a maximum of 2.4 oz per hour. What type of unit would ever overheat to pump 2.4 oz per hour of fluid? This makes no sense to me. I am skeptical that the motor will run constantly for 1 hour. Do you believe this?

@Stenner Tech Support , can you please confirm with the engineering/design team. Will the motor of the LD truly be running the whole time?
Allen

 

[AllenA]

From

Peristaltic pump - Wikipedia

en.m.wikipedia.org

"Peristaltic pumps may run continuously, or they may be indexed through partial revolutions to deliver smaller amounts of fluid."

I am hoping for the latter which should eliminate any heating issues.

 

[Stenner Tech Support]

Hi jonpcar, you are correct. And I did call today to get some of my assumptions clarified.
Hi Stenner Support. Thank you for your input.

I got the below questions answered today regarding the Econ LD, specifically, the E10LHM w/ flow rate: 0.04 - 2.4 oz / hr. Here are the details:

- Operating Temperature
--- Thermal turn off switch is similar as other pumps. Means that it will shut down at 125 F just like the others.

Why does the manual state that the max fluid temp is 40 C? Will it degrade the tubes faster?
--- Tubes can get gummy when liquid is too hot.
--- This applies to any pump using the same tube (Sanoprene).

Many in AZ and hot climates are using Stenner Pumps. Wouldn't the tubes of the other pumps also be subjected to the same temp restrictions?
--- Yes.

What is happening when it is idle?
--- It is never idle, there are no internal timers. Motor runs constantly.

How can it pump out only 0.04 oz / hr?
--- You are fine tuning the RPMs of the motor with the potentiometer. Motor is running constantly at extremely small speeds.

Can it be controlled using a flow switch?
--- Not directly. Must go DIY directly to pump or put something in between.

@Stenner Tech Support, please let us know if I misunderstood any of the answers.

As for my particular use case, phone tech support (thank you BTW) believes that it makes total sense to use it for my application of MA running all day. I am not thrilled with the idea that the motor is constantly running even at such low speeds. I cannot even imagine how it can "run" at such small speeds to only pump out 0.04 oz / hr. Maybe I am still missing something here but I did ask the question 2 times and it seems that the motor will be running the whole time so no internal ON/OFF to just output the small amounts / hr. I am concerned with the fact that the pump will run continuously all day. However, I am no longer concerned with the operating temp max as it would run just like any other of their pumps and since others are using them in AZ then it should work for me. I guess there is no way to find out what will happen exactly until I try it first hand. I will give it a shot and order one and post additional information here to let the community know how it goes once installed and running.

Thanks again jonpcar for indulging with my assumption! Have a great summer to you and TFP!
Allen

The tube size in conjunction with the low RPM's is going to be the determining factor in output. The smaller tube with the low RPM's results in very low dosage.

As we discussed it is a bit similar with the Classic Series (however the RPM's don't change, we index with the Feed Rate Control) the smaller the tube the lower the output.

 

[jonpcar]

Allen, running the acid injection continuously does seem to simplify some things for your situation (especially since you know your pool's exact acid requirements) but it wouldn't apply to my situation, at least currently:

I don't run my pump 24/7 and my pump schedule changes season to season. I run my waterfalls sporadically (based on kids swimming and based on a schedule) and in the future I will be experimenting with aeration to cool the pool in the summer's early morning hours. During swim season, my pool gets irregular use. Worst of all, as I mentioned before, I have been lax with pH control priior to this season and don't know (and have no record unfortunately) about how my pool's acid needs change based on all these circumstances.

So currently I am keeping careful records of my pool's pH and my acid dosing to build a record. I make tweaks to the schedule and use "manual additions" when I need to make adjustments. The thing I really, really dislike (soon be solved for me), is that I currently have to go out to the pool pad area to make these adjustments on my sprinkler/Stenner timer. Despite that inconvenience, the "manual additions" of acid are much simpler and safer because I don't have to deal with the gallon jugs, I simply push buttons. You won't have to deal with changes for your scheduled dosing, since you have that tuned, but you will have to think about any manual dosing that you might need to do: jugs or turning the dial up temporarily?

Finally, some advice when you settle on your Stenner. The dispersal rates they quote are only guidelines. They recommend that you test your actual device in the field to measure its actual dispersal rate. I did that with water in my kitchen before installing it, I figured close enough. My 10gpm/day Stenner (.89 oz/min) actually disperses about 1.1oz/min, about a 20% difference. You will want to make sure to calibrate various positions of your dial on your Econ DL to actual dispersal numbers... AND make sure those rates are repeatable when "redialed" (how touchy is that potientiometer's position?).

 

[scottts]

Hi fellow Arizonans!

Interesting concept here dosing MA continuously. It looks like you're going to try this open loop, without any sort of electronic monitoring feedback to prevent overdosing? I'd be afraid of overdosing unless you are going to monitor it manually, often.

My MA needs vary too much, based on detritus deposited in the pool by trees and storms and whether my SWCG is running, to rely on average usage rates. Especially since too much or too little MA can have a big impact on CSI. I suppose if your manually testing frequently you can correct, but then what is the advantage of continuous low dose?

Just last week two big mesquite trees started dumping HUGE amounts of pollen into the pool at the slightest breeze. I was taking literal buckets full of the stuff out every morning until my wife figured out that spraying the trees with water knocked most of the pollen off so it couldn't blow in the pool. I guess the pollen must be acidic because my pH dropped enough for my system to not dose MA for two days even with heavy SWCG usage, which normally burns acid in my pool. I would expect when a monsoon dumps sand into the pool, the opposite will occur - pH will rise and MA demand will go up.

I also wonder, but don't know, what low continuous dosing might do to TA. Will it reduce it more than periodic dosing does?

 

[jonpcar]

Hey Scott, thanks for joining...I mentioned a bunch of things that impact my pH...things that I somewhat control, I didn't even think about all those outside influences that potentially impact it even more. I may be fighting with some of that now due to pollen from my neighbors tree. In any case, like you, I don't think I will ever come close to a "set" acid dosing, which is why you know I am considering a pH probe in the future to provide some feedback. But that's a different discussion and first I want to gather more data .

A quick question while you are here...high free chlorine levels impact the reliability of pH drop tests...Do you know if that is also the case for your pH probe? Thanks.

 

[scottts]

I don't think the probes are affected by FC. Perhaps at some ungodly level, but I've had FC up to 20 and noticed no variation in pH reading.

I think the pH drop test suffers from the indicator getting bleached out by the high FC. That's a chemical mechanism that doesn't have an analog with the pH probe.

If I have to pick the most reliable thing about the intellichem system it would be the integrity of the pH measurement and dosing function.

 

[AllenA]

Hey Scotts,
Thanks for joining.
So guys, I went for it and ordered it despite the motor being ON all the time which I would have preferred to be timed for such small dosing. I talked with a good friend who is knowledgeable in motors and general things electrical about the potential of overheat and he does not seem to be too concerned. I should receive it next week hopefully and will let you all know how it goes. He also reassured me that it would cost me pennies per day to run based on it's specs. I will try to get one of those units that can measure power consumption to double check the numbers.

Now, just so you know, I also do have alternatives when all else fails and that was always part of the plan. I could just buy the larger tube and run it sub-daily with a timer if I need to as a mitigation plan. The larger hose can deliver 8 oz per hour which means I could run it for 2-3 hours per day to get max maximum needs. I hope not but plan B is available.

As for dosing, of course I will be monitoring MA regularly. That part does not go away, not yet at least. And then all I have to do is dial up or down to keep it at target. As for my particular pool, I barely have anything falling into it. Just the usual AZ dust and maybe very small leaves from the bushes and smaller trees here but nothing major. So my fluctuations will be minimal from that side of things. However, I do have the kids splashing and running the waterfall and slide which does disrupt things, thus manual monitoring will still be there. I would just dial up or down as I learn how to use the new system. Of course keeping the TA in check will play a big role into it anyway.

Also, I do expect that I may have to either shut it down / lower it or manually dose in extreme cases. But when you think about it, the more you manually intervene in any form, the more you lose the ability to find the "perfect" setting of the pump for that period of year. It might be best to let PH float up or down a bit and not change things and see what happens over a few days.

I am also fine with the fact that the rates may not be perfect. I am not too concerned with that as long as the potentiometer is more or less accurate and it seems that it is. What I mean is, let's say the min and max are not truly 0.04 -> 2.4 oz/hr. This is no problem for me. After all, all I care about is that when I set the potentiometer to say 40, this is good for this week. Maybe next week it would be 42 or 38, whatever. Who cares what the actual dose will be. I won't be bothered. It seems however that we can rely on those as long as pressures are within the 80 psi. Seeing that the pump will run at low RPM, I imagine my pressure should not reach 80 psi. But when the kids run the waterfall, pressure will rise but not sure to what exactly. Anyway, I am more concerned with the potentiometer being reliable. @Stenner Tech Support, one more question for you please because I don't think I could find the information. The actual dial goes from 0 to 100. Is that percentage? I can see from the picture that the numbers are scaled. I imagine that was purposely done. Even between the 20 and 30 mark seems they are a bit separated. Can this be considered the percentage of 2.4 oz / hr using the smallest hose? Is it expected that the setting of 50 for example will pump out half the max of 2.4, meaning 1.2 oz/hr?


My future plan...:
- Protection to ensure flow. Will look into the simplest way to stop it from running when there is no flow. I'm not there yet.
- Add a PH monitor. I did read about concerns over those and will continue to evaluate to find the best course of action.

Now there were a couple of threads discussing the injection of MA before the salt cell and others commented that it may not be a good idea. But that was based on the higher flow rates, trying to push as much as possible in the shortest amount of time. Since my estimated max output for my needs would be 1.5 oz per hour with this pump, I wonder if this is a concern. If I have a flow sensor protection on the pump, I wonder if there is any danger to the cell? I doubt that such small doses can damage the cell. But then again, I wonder if such small doses will help keep it clean either. I'm not sure if I will try it this way but maybe, we'll see, unless someone knows of a really bad reason not to. I probably won't easily find any info on this. And I am sure the cell manufacturer will say flat out NO but that's without any tests.

I will let you all know how it goes once I have it installed. I installed yesterday the RJ60+. Yay! Replaced a Zodiac LM-24 which just gave me so much trouble over the years. A bit of plumbing challenges but overall all is good. Love the features so far with at least the salt reading.
Allen

 

[RDspaguy]

Just joining in, sorry if I repeat anything.
I am not a fan of unmonitored dosing. Too many variables.
Pentair makes a decent residential system that is reasonably priced and functions well.

Pentair IntellipH Controller w/ Acid Canister - 521377 - INYOPools.com

www.inyopools.com

I would not inject acid before the salt cell, unless you enjoy replacing salt cells. The metal grids will not like the low ph.

 

[AllenA]

Hi Spaguy,
Thanks for your input, but...
Let's make sure we are talking about the same thing.
I never said I am not monitoring. I said I want to low dose 24/7 VS. High dose sub daily. I will manually monitor as we all need to do.

If I were to add a flow sensor / controller, I contemplate the pre SCWG setup. My pool's worst demand in the summer, requires 1.5 oz MA per hour. That's 0.025 oz per minute. A drop! The pump will be running and moving say 10 GPM at a min with the speed of 1100 RPM? That will not affect PH. But I also as I said wonder if it were to do any good at all at keeping the cell clean. The MA would be so diluted that it may actually be useless after all. Maybe it may do something at the higher doses which will not be what I will do.
Allen

 

[Stenner Tech Support]

Hey Scotts,
Thanks for joining.
So guys, I went for it and ordered it despite the motor being ON all the time which I would have preferred to be timed for such small dosing. I talked with a good friend who is knowledgeable in motors and general things electrical about the potential of overheat and he does not seem to be too concerned. I should receive it next week hopefully and will let you all know how it goes. He also reassured me that it would cost me pennies per day to run based on it's specs. I will try to get one of those units that can measure power consumption to double check the numbers.

Now, just so you know, I also do have alternatives when all else fails and that was always part of the plan. I could just buy the larger tube and run it sub-daily with a timer if I need to as a mitigation plan. The larger hose can deliver 8 oz per hour which means I could run it for 2-3 hours per day to get max maximum needs. I hope not but plan B is available.

As for dosing, of course I will be monitoring MA regularly. That part does not go away, not yet at least. And then all I have to do is dial up or down to keep it at target. As for my particular pool, I barely have anything falling into it. Just the usual AZ dust and maybe very small leaves from the bushes and smaller trees here but nothing major. So my fluctuations will be minimal from that side of things. However, I do have the kids splashing and running the waterfall and slide which does disrupt things, thus manual monitoring will still be there. I would just dial up or down as I learn how to use the new system. Of course keeping the TA in check will play a big role into it anyway.

Also, I do expect that I may have to either shut it down / lower it or manually dose in extreme cases. But when you think about it, the more you manually intervene in any form, the more you lose the ability to find the "perfect" setting of the pump for that period of year. It might be best to let PH float up or down a bit and not change things and see what happens over a few days.

I am also fine with the fact that the rates may not be perfect. I am not too concerned with that as long as the potentiometer is more or less accurate and it seems that it is. What I mean is, let's say the min and max are not truly 0.04 -> 2.4 oz/hr. This is no problem for me. After all, all I care about is that when I set the potentiometer to say 40, this is good for this week. Maybe next week it would be 42 or 38, whatever. Who cares what the actual dose will be. I won't be bothered. It seems however that we can rely on those as long as pressures are within the 80 psi. Seeing that the pump will run at low RPM, I imagine my pressure should not reach 80 psi. But when the kids run the waterfall, pressure will rise but not sure to what exactly. Anyway, I am more concerned with the potentiometer being reliable. @Stenner Tech Support, one more question for you please because I don't think I could find the information. The actual dial goes from 0 to 100. Is that percentage? I can see from the picture that the numbers are scaled. I imagine that was purposely done. Even between the 20 and 30 mark seems they are a bit separated. Can this be considered the percentage of 2.4 oz / hr using the smallest hose? Is it expected that the setting of 50 for example will pump out half the max of 2.4, meaning 1.2 oz/hr?
View attachment 137479

My future plan...:
- Protection to ensure flow. Will look into the simplest way to stop it from running when there is no flow. I'm not there yet.
- Add a PH monitor. I did read about concerns over those and will continue to evaluate to find the best course of action.

Now there were a couple of threads discussing the injection of MA before the salt cell and others commented that it may not be a good idea. But that was based on the higher flow rates, trying to push as much as possible in the shortest amount of time. Since my estimated max output for my needs would be 1.5 oz per hour with this pump, I wonder if this is a concern. If I have a flow sensor protection on the pump, I wonder if there is any danger to the cell? I doubt that such small doses can damage the cell. But then again, I wonder if such small doses will help keep it clean either. I'm not sure if I will try it this way but maybe, we'll see, unless someone knows of a really bad reason not to. I probably won't easily find any info on this. And I am sure the cell manufacturer will say flat out NO but that's without any tests.

I will let you all know how it goes once I have it installed. I installed yesterday the RJ60+. Yay! Replaced a Zodiac LM-24 which just gave me so much trouble over the years. A bit of plumbing challenges but overall all is good. Love the features so far with at least the salt reading.
Allen

That is correct. The numbers represent a percentage of the pumps maximum output. There is +/- 2% reproducibility so outputs may vary slightly.

 

[scottts]

Hey Scotts,
Thanks for joining.
So guys, I went for it and ordered it despite the motor being ON all the time which I would have preferred to be timed for such small dosing. I talked with a good friend who is knowledgeable in motors and general things electrical about the potential of overheat and he does not seem to be too concerned. I should receive it next week hopefully and will let you all know how it goes. He also reassured me that it would cost me pennies per day to run based on it's specs. I will try to get one of those units that can measure power consumption to double check the numbers.

Now, just so you know, I also do have alternatives when all else fails and that was always part of the plan. I could just buy the larger tube and run it sub-daily with a timer if I need to as a mitigation plan. The larger hose can deliver 8 oz per hour which means I could run it for 2-3 hours per day to get max maximum needs. I hope not but plan B is available.

As for dosing, of course I will be monitoring MA regularly. That part does not go away, not yet at least. And then all I have to do is dial up or down to keep it at target. As for my particular pool, I barely have anything falling into it. Just the usual AZ dust and maybe very small leaves from the bushes and smaller trees here but nothing major. So my fluctuations will be minimal from that side of things. However, I do have the kids splashing and running the waterfall and slide which does disrupt things, thus manual monitoring will still be there. I would just dial up or down as I learn how to use the new system. Of course keeping the TA in check will play a big role into it anyway.

Also, I do expect that I may have to either shut it down / lower it or manually dose in extreme cases. But when you think about it, the more you manually intervene in any form, the more you lose the ability to find the "perfect" setting of the pump for that period of year. It might be best to let PH float up or down a bit and not change things and see what happens over a few days.

I am also fine with the fact that the rates may not be perfect. I am not too concerned with that as long as the potentiometer is more or less accurate and it seems that it is. What I mean is, let's say the min and max are not truly 0.04 -> 2.4 oz/hr. This is no problem for me. After all, all I care about is that when I set the potentiometer to say 40, this is good for this week. Maybe next week it would be 42 or 38, whatever. Who cares what the actual dose will be. I won't be bothered. It seems however that we can rely on those as long as pressures are within the 80 psi. Seeing that the pump will run at low RPM, I imagine my pressure should not reach 80 psi. But when the kids run the waterfall, pressure will rise but not sure to what exactly. Anyway, I am more concerned with the potentiometer being reliable. @Stenner Tech Support, one more question for you please because I don't think I could find the information. The actual dial goes from 0 to 100. Is that percentage? I can see from the picture that the numbers are scaled. I imagine that was purposely done. Even between the 20 and 30 mark seems they are a bit separated. Can this be considered the percentage of 2.4 oz / hr using the smallest hose? Is it expected that the setting of 50 for example will pump out half the max of 2.4, meaning 1.2 oz/hr?
View attachment 137479

My future plan...:
- Protection to ensure flow. Will look into the simplest way to stop it from running when there is no flow. I'm not there yet.
- Add a PH monitor. I did read about concerns over those and will continue to evaluate to find the best course of action.

Now there were a couple of threads discussing the injection of MA before the salt cell and others commented that it may not be a good idea. But that was based on the higher flow rates, trying to push as much as possible in the shortest amount of time. Since my estimated max output for my needs would be 1.5 oz per hour with this pump, I wonder if this is a concern. If I have a flow sensor protection on the pump, I wonder if there is any danger to the cell? I doubt that such small doses can damage the cell. But then again, I wonder if such small doses will help keep it clean either. I'm not sure if I will try it this way but maybe, we'll see, unless someone knows of a really bad reason not to. I probably won't easily find any info on this. And I am sure the cell manufacturer will say flat out NO but that's without any tests.

I will let you all know how it goes once I have it installed. I installed yesterday the RJ60+. Yay! Replaced a Zodiac LM-24 which just gave me so much trouble over the years. A bit of plumbing challenges but overall all is good. Love the features so far with at least the salt reading.
Allen

I think you are right to be worried about the long term reliability of the pot. I'm an EE and I've designed products for the automotive, oil production, and other heavy industries for 35+ years. We actually banned the use of pots in our designs because they were the #1 failure mode in automotive designs for us. That was in the 90's. Pots are mechanical devices and they ALL eventually fail. Ever had a radio where the volume jumped around blasting your ears when you adjusted the knob - that's a dirty pot. OK, off my soap box about that.

My PB piped the acid inject right before the SWCG. I question it but my cell is pristine so far, My system only doses to a setpoint relatively infrequently for a short period of time. I think with the small dose rate, like 1oz/sec say, and the massive water flow through there >25GPM specification min for an IC-40, the potential for serious erosion of the plates is minor. Plus I use 1:1 diluted acid per Pentair's recs.