Pump size

[Snups]

We have a cement pond. It is 3ft x5ft X 2ft deep. I just bought a 12 inch waterfall for it. It will be about 3 ft above water. I would like a pump with a fountain attached. What size pump should I get?

 

[GBBUDD]

thats your call what do you want to see........

 

[j.w]

@Snups
Yep do you want a gusher or a quiet trickle, all up to you.

 

[Snups]

thats your call what do you want to see........

Thanks for the video. That helps me a lot!

 

[Snups]

View attachment 129193@Snups
Yep do you want a gusher or a quiet trickle, all up to you.

Thanks.

 

[GBBUDD]

if you have a long pipe you will loose water flow amounts if you are pushing water up the pipe to your waterfall or bog you will loose flow thats called head pressure

 

[brc]

You can always use more than one pump as well.. even through the same pipe if you use check valves or.. regular valves. The idea would be to have a small one keeping the filtering going around the clock, and then a monster one that runs when you're out there. That way, you can have huge waterfalls and streams, but skip the high electric bills.

Ditto on the piping. Since you're paying for electric to pump water through there, I'd install big pipe - it costs very little extra, and saves energy forever.

 

[GBBUDD]

not sure if I follow or not, but if I do, do not run two pumps on one pipe at the same time. you can burn out the smaller pump

 

[brc]

not sure if I follow or not, but if I do, do not run two pumps on one pipe at the same time. you can burn out the smaller pump

Now that you mention it.. I probably should have been more clear

Two pumps into one pipe would be ok, but the pipe would have to be big enough that the backpressure stays low - which would be a lot bigger than most people probably run for the same pump. IE, a 1000 and 3000gph pump should be ok sharing 10-20ft of 4 inch PVC pipe, but a 1.5in pipe might kill one. If they have similar "head" ratings, that would probably help too.

Each pump just needs to be flowing a normal-ish amount of water (and in the right direction).

 

[GBBUDD]

They will work against each other much better off with a big pump behind a ball valve the party pump and same with all day pump shut the ball valve . or just run two separate lines. I'm not a hydroxy expert but I'd bet its a bad idea for two in one. I understand the concept of so large a pipe but now you have a lot more weight/head the pumps will fight.

 

[brc]

It seems intuitive that "head" pressure would depend on the total weight of the water in the pipe (ie, a big pipe fill of water would have more pressure than a small one), but it actually doesn't - it only depends on the height of water.

A thin vertical tube full of water that's (say) 4ft tall will have exactly the same pressure at the bottom as a 4ft tall barrel of water, or a 4ft deep pond. It's also the same pressure as a 500ft long pipe full of water that has one end 4ft higher than the other. They sure don't weigh the same amount.. but the pressure per square inch is the same.

Of course, that changes when the water starts to move - if you push 3000GPH through a horizontal 4 inch pipe, the pressure at the pump end is very low. Try to push the same flow through a garden hose, and the hose will probably explode.

Still, it's kind of a moot point - a valve big enough to shut off any pump you'd want in a pond, would probably cost more than a second run of pipe anyway