DC Controllable Pumps vs AC Pumps

[sirreal63]

I had missed the 1/2" returns earlier, if you can manage 1" all the way up to the 1/2" it will help, it will not ever make the high flow with a submersible pump, the restriction is still there but eliminating as much as you can before the restriction will help.

How much flow are you hoping to get?

 

[d2mini]

How much flow are you hoping to get?

Probably more than what is physically possible. :lol:

I have 5x flow right now which most would say is perfect.
If I could break the 1000 gph barrier, that would be awesome and I'd be over 8x.

FWIW, Elos claims the overflow can handle 2900 gph and my model comes with optional pump rated at 1585gph.
So I would think 1000gph would be possible with the right plumbing setup.

 

[sirreal63]

I would change plumbing before buying a new pump. If buying a new pump I would go with the Fluval SP6. With the head and friction loss, it won't pull the rated 135 watts. You may find you have more flow than you thought was possible with a pump designed for a little head.

 

[Gorgok]

Interestingly, the flow does seem 'correct' for what the pump is and your setup. 21.5 feet of head sounds nice, but its only about 9.5 psi. 9.5 psi puts the flow in low/gravity range on this chart here. Your ultimate restriction is either the dual locline, the barb fittings, or the 3/4 flow meter (specifically the point where the sensor is). Whichever has the smallest area (they are all pretty close). But its definitely under the 3/4" pipe point. Currently the flow meter probably isn't the limit, as you said it had no impact, but upsizing the barbs (or eliminating, whatever) and the locline would only get you to the flow meter in size, then that is the limit. So, more psi...

 

[d2mini]

Interestingly, the flow does seem 'correct' for what the pump is and your setup. 21.5 feet of head sounds nice, but its only about 9.5 psi. 9.5 psi puts the flow in low/gravity range on this chart here. Your ultimate restriction is either the dual locline, the barb fittings, or the 3/4 flow meter (specifically the point where the sensor is). Whichever has the smallest area (they are all pretty close). But its definitely under the 3/4" pipe point. Currently the flow meter probably isn't the limit, as you said it had no impact, but upsizing the barbs (or eliminating, whatever) and the locline would only get you to the flow meter in size, then that is the limit. So, more psi...

Ooof. Ya, that's the same chart I was looking at to find the max flow of 1/2" pvc.
Where did you find the psi info for the Vectra?
I wonder how other pumps compare?

So I have the materials to replumb the section between the flow meter and the overflow. That will get rid of two barb connectors and a 45 degree elbow, replacing it all (about 16-18") with one long sweep of flex pvc.

Will be interesting to see what kind of improvement that gains me, and then this weekend I should have the coupling for the Vectra and can get rid of that section of barbs, including the 90 degree barb.

So it will be all 1" from the pump to the overflow, except for that short section of 3/4 through the meter.

 

[d0ughb0y]

if you take the ratio of the pipe diameter squared, the flow will increase 1.777x for 1:0.75, and 4x for 1:0.5. So new flow should be about 1067gph if restriction was 3/4, or 2400gph if the restriction was 1/2.

 

[tkeracer619]

Edit: Nevermind............ I was thinking the new Apex flowmeter setup... not GHL...




So I did this 5 or so years ago with my ReefAngel. Unless I am mistaken they are using the same sensors. Maybe they made them better but I never had any issues. I don't currently use my controller but plan on putting it back online on the 600gal.

Maybe you could try out the 1" instead of the 3/4"


1/2" Sensor
https://www.seeedstudio.com/G1&2"-Water-Flow-Sensor-p-635.html
3/4" Sensor
https://www.seeedstudio.com/G3&4"-Water-Flow-Sensor-p-1083.html
1" Sensor
https://www.seeedstudio.com/G1"-Water-Flow-Sensor-p-1671.html

 

[d2mini]

Actually, just realized (i forgot) that the I.D. of the flow sensor is .98" (25mm). It's the couplings that convert it to USA Imperial sizes that is 3/4".
Probably explains why I didn't really see any difference in flow after installing.

 

[Gorgok]

Where did you find the psi info for the Vectra?
I wonder how other pumps compare?

I was using the max head as the max pressure, which is simple enough to convert:
p = 0.433 h SG

where

p = pressure (psi)
h = head (ft)
SG = specific gravity of the fluid

But that doesn't take into account losses you will have because of actual head, plumbing etc. Actual performance would depend on the curve, which is dependent on the impeller/volute design more so than the motor driving it, but it won't get any better than max head.

Pressure pumps typically have a skinnier impeller and are larger in diameter. These DC pumps we have had so far all have fairly small diameters and thick impellers. That may be why a submersible AC pump might beat them, as they are generally pretty skinny and large in diameter compared to the motor rotor. Most of them are just too small to compete though, not enough power and impellers too small.

A DC pump could do that as well if there were a volute and impeller made to do pressure. I think its just that they are easier to sell with high flow numbers so that is what they have been going for.

 

[d2mini]

Ok, i replaced one 1" 45 degree elbow and two 3/4" barbs and silicone tubing with 1" flex pvc that connects to a 1" to 3/4" adaptor at the overflow.

With this, I gained maybe 35 gph. lol

But I still have the restriction between the pump and the ball valve to deal with.
That should free up a good amount.

 

[Dross]

All of our pumps, even the ones we call pressure rated, would be considered low pressure by pool/spa industries that these sites serve. I would not expect to get anything more than the low pressure column flow rates. If the EcoTech perforamance curve is accurate, you are operating at 15 ft of head loss at 600 GPH or about 7 psi. I think you will need a 1.25 or even 1.5 inch main header to have any hope of getting to 1000 gph, especially considering the 1/2" returns.

 

[kc350twin]

DC Controllable Pumps vs AC Pumps

I don't think you will see significant flow increases until you increase the size of your pipe and ditch as many restrictions as possible. I tried so many options on my set up to achieve Triton turnover rates and until I increased the pipe size and ditched the 3/4 nozzles at the end nothing made huge impacts. Mag 18 with 1 1/2" pipe from top to bottom. 10ft ish of head and barely 1000gph.






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[d2mini]

I don't think you will see significant flow increases until you increase the size of your pipe and ditch as many restrictions as possible. I tried so many options on my set up to achieve Triton turnover rates and until I increased the pipe size and ditched the 3/4 nozzles at the end nothing made huge impacts. Mag 18 with 1 1/2" pipe from top to bottom. 10ft ish of head and barely 1000gph.






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I totally agree, but the problem I'm faced with in this particular case is that I can't do anything about the return plumbing inside the overflow.
I don't know exactly what's going on inside, but the entry hole at the bottom of the overflow is 3/4" and at some point inside it splits, and exits the overflow inside the display from two 1/2" outlets.
That said, with high pressure, 1/2" pipe has the capability to flow much more than it currently is.

So due to the amount of restriction inside, outside improvements are only going to take me so far. Doing what I can though. Will end up with 1" straight from the pump to the overflow with just those two 1"-3/4" adaptors to pass through on each end of the .98" flow sensor.

 

[iced98lx]

I think as you've realized you're goign to hit a top end with the L1 and require some sort of higher pressure pump that is designed to push through smaller pipe.

 

[d2mini]

I think as you've realized you're goign to hit a top end with the L1 and require some sort of higher pressure pump that is designed to push through smaller pipe.

Exactly... which brings us full circle back to my original post, asking if there is a submersible pump that would offer a better power curve and provide me with more flow than I'm getting currently.

 

[jason2459]

Exactly... which brings us full circle back to my original post, asking if there is a submersible pump that would offer a better power curve and provide me with more flow than I'm getting currently.

Abyzz A200 31' head rated

Deepwater Aquatics BLDC 15 23.6' head rated(fragtastic shows it in stock)

Jebao DCP 18000 possibly. "rated" for around 30' head

 

[kc350twin]

DC Controllable Pumps vs AC Pumps

I haven't seen your build thread in a while but if memory serves me correct your tank is very visible and pleasing to the eye.

Is a over the back pipe possible bypassing the Elos return? Just food for thought.

I am very interested if the above mentioned pumps are any better of pressuring your plumbing. The BLDC has been out of stock everywhere and looks to be the same or similar to the Ecotech. I will be following for sure.




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[iced98lx]

Exactly... which brings us full circle back to my original post, asking if there is a submersible pump that would offer a better power curve and provide me with more flow than I'm getting currently.

Yea, sorry I was trying to subtly point out that you were already pretty aware of the restrictions on your setup to those who insist that you can you achieve what you want with the L1, in this situation you had already realized that was unlikely and would prefer to change pumps vs attempting to circumvent the return setup in place with the tank.

 

[jason2459]

Yea, sorry I was trying to subtly point out that you were already pretty aware of the restrictions on your setup to those who insist that you can you achieve what you want with the L1, in this situation you had already realized that was unlikely and would prefer to change pumps vs attempting to circumvent the return setup in place with the tank.

I would still correct the plumbing to be more efficient. :thumbsup:

 

[d2mini]

Abyzz A200 31' head rated

Deepwater Aquatics BLDC 15 23.6' head rated(fragtastic shows it in stock)

Jebao DCP 18000 possibly. "rated" for around 30' head

Dang.
The numbers on those Deepwater pumps are pretty astounding compared to the Vectras.
Are they accurate?
The body of the pump looks identical.
But the outlet is 1.5" vs 1".
And I'd still be taking it down to 3/4" and 1/2" by the time it hit my returns.