Water Feature Pump

[Cinic]

The picture below shows my water feature of the 3 spill pots.



This picture shows my pump setup.




The one on the left is the pump for the feature. It is a Pentair Challenger High Pressure CHII - NI - 1 1/2F. As you can see, the (3) outputs to the individual pots are severely throttled back. This is way more pump than needed for the application.

I'm considering swapping that pump out for a specialty waterfall low head type pump. However, I have a couple questions.

1. How do I size the waterfall pump? There's not much vertical rise. The highest pots is about 42" above the water. Without measuring the head, I would imagine it's in the lower range of the waterfall pump capacity. But for flow, do I dial in the pot flow where I like it, then get a 5 gal. bucket and figure out the rate of flow by how long it takes to fill? Seems kinda simplistic.

2. Do the economics exist to make this swap? This thing doesn't run a lot. Maybe 35 hours/week worst case if I run it all day on the weekends. We have time-of-use power so our off-peak rate is under $0.10. That's around $5 week savings between the existing 11.2A pump and a new 4.8A pump. Low end, new pumps are $500 so we're looking at a two year break even. Now if my existing pump were broken, there's no question I'd just be dealing with question 1. But I have an existing pump that 'works' but is just not as efficient as it could be.

I understand there will be a lower noise benefit as well. And that's worth something.

Thoughts welcome.

 

[mas985]

If the flow rate is fairly low, which it seems to be, then you might consider running the pots off the main pump with redirected flow. A waterfall pump is made for low head high volume waterfalls which is opposite to what you have so I would not recommend that.

 

[Cinic]

I'll have to get a rough idea of flow rate. I think it's more than it looks from the photo. The water pours out of there pretty good.

Not too keen on tying it all together as the feature imparts a lot of aeration. And I don't want to manually divert flow when I want the pots because then I can't automate the circulation with a simple timer. Although, if I skip buying a new pump, I'm that much closer to an automation sub-panel which could automate some flow to the pots...

 

[mas985]

The way I deduced that it was low flow rate is by the pipe size feeding each pot. Those pipes can't really support much in the way of flow rate without creating huge head loss but then you would not need to close off the valves so much so the flow rate must be pretty low.

Although, if I skip buying a new pump, I'm that much closer to an automation sub-panel which could automate some flow to the pots...

A much more energy efficient solution too.

 

[JoyfulNoise]

What about modifying the pump with a lower horsepower motor (do they make a 1HP or 3/4HP motor for that wet end?)? Or going with a two speed motor for efficiency?

I'll admit I instigated this thread about using a waterfall pump from the OPs previous SLAM thread without seeing the plumbing at the pad. Had I seen this piping setup, I would have been much more circumspect about suggesting a pump change. My bad...




Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[mas985]

You would also need to change the impeller but even the smallest impeller would probably deliver far too much flow rate for those pots. It is far more efficient to run it off the main pump than it would to significantly restrict the flow from a second pump.

 

[JoyfulNoise]

You would also need to change the impeller but even the smallest impeller would probably deliver far too much flow rate for those pots. It is far more efficient to run it off the main pump than it would to significantly restrict the flow from a second pump.

I see that.

However, since your cutting up PVC, what's to be done with the wall return feeding the water feature pump? I guess you'd have to cut it into the suction side of the pool pump or else you'll have a dead wall return with a pipe full of stagnant water....


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[Cinic]

I'll admit I instigated this thread about using a waterfall pump from the OPs previous SLAM thread without seeing the plumbing at the pad. Had I seen this piping setup, I would have been much more circumspect about suggesting a pump change. My bad...

Don't apologize. I'm happy to learn something with a good discussion.

I'll waste some time this weekend and try to get an idea of the flow rate. Just for ha-ha's. Then probably put this idea to bed. There's going to be a pool update somewhere in the not-so-near future and I'll re-evaluate the whole system then. If the motor craps out before that, I'll look at the lower HP motor/impeller replacement for some incremental savings in the interim.

 

[rphpool]

Is your current pump something that could be used later down the road if another pump fails? You can always change to more efficient pump and save it for later. Automation is the way to go but big $$ layout upfront.

 

[Cinic]

I don't (yet) know enough about pumps and pump motors to know if that existing pump would work in place of my current main pump as a replacement.

 

[pooldv]

My recommendation would be if either pump goes out to get and Intelliflo VS pump, 011018, and replumb at the same time. Mine runs everything, waterfall, solar panels, skimmer, filter, SWG no problem and never above 2500 rpm (max is 3450). My waterfall is valved with a 3way valve with the pool returns so I can dial in the amount or flow to the waterfall with the 3 way valve and variable speed pump. It is easily capable of running solar, waterfall and everything at the same time with a lot of waterfall, usually at 1950 rpm using 550 watts. There are pics of my equipment pad in my build thread, link in sig.

It is also ridiculously efficient. For normal skimming and making chlorine it runs at 1100rpm and uses 150 watts. I can run it 24x7 for less than 12 bucks a month at 10.25c/kWh. We often need to in spring and fall because we have lots-o-trees helping us with pool maintenance!

This pump
Pentair IntelliFlo Variable Speed Pump 011018 | Pentair 011018