gonna run 2 tanks w/ poseidon external pump.
is there any difference between having the pump higher, so it pushes water less in height, and having it lower, so it doesn’t have to suck water up? or is it half and half?
i wanna get maximum water flowing out into the 2 tanks.
i can raise the pump 8 inches, but isn’t my gain in head pressure negated by having to lift the water that extra 8 inches?
You dont want to have the pump any higher then the low water level of your sump. Those pumps are not good at sucking water and if the power ever gos out, when it comes back on the pump will start dry and may never be able to start sucking water and you could burn up the pump.
If you want to get the max flow out of the pump what you can do is upsize the pipe coming out of the pump. Your pump has a one inch outlet so you could go to 1 1/2" or even 2". Doing this wont increase the flow but what it will do is decrease frictional lose so you will get more gph from a larger pipe.
Besides all that, i think you will have plenty of flow just the way you have it now. You dont need a ton of flow racing through your sump. IMO thats just a waste.
thanks chris/barb. i appreciate it. and no i’m not gonna replace plumbing w/larger pipe
[quote=“Chris_Barb, post:2, topic:2433”]
If you want to get the max flow out of the pump what you can do is upsize the pipe coming out of the pump. Your pump has a one inch outlet so you could go to 1 1/2" or even 2". Doing this wont increase the flow but what it will do is decrease frictional lose so you will get more gph from a larger pipe.[/quote]
Nice tip!
just be sure to keep in mind that increasing the diameter of the outlet piping will reduce the effecive height that the pump is able to pump water. i think… ;D
So the question is will it increase head pressure decreasing flow contacting the benefits of the friction reduction. I believe Chris is saying it does not.
How would you increase the diameter of the return pipe, and still have a seal between the pump and piping…
As we use the term in the hobby, head pressure is usually thought of the amount of vertical feet a pump can pump water before it cant. The biggest factor for calculating head pressure on a vertical run is gravity, not friction. The amount of force that gravity is going to apply is going to be directly related to the amount of mass which is given by the volume of water which will increase as the pipe increases. Just like anything, there is going to be a trade off. Chris is absolutely right, friction plays a huge part in how much water is moved in a given amount of time. If the run was horizontal, the results would probably be fairly significant. I might be a physics geek, but hydrodynamics isnt a strength so im not about to start busting out equations >LOL< However, if anyone wants to see the physics of the scenario, take any pump and connect a straight vertical pipe on its output that matches the diameter of the output. The number of feet that the pump can move the water vertically should be roughly right around the max head given by the manufcaturer. Now increase the diameter of the pipe and you will decrease the max head even though the friction is less simply because gravity has a much more significant effect on the water than the friction. The angle of the pipe is roughly 90 degrees relative to the surface of the floor. If you change this angle, the net distance that the water will now travel is more, but the vertical distance will still be the roughly the same.
john - bushings and adapters.
[quote=“logans_daddy, post:5, topic:2433”]
just be sure to keep in mind that increasing the diameter of the outlet piping will reduce the effecive height that the pump is able to pump water. i think… ;D[/quote]
No it dosent effect head at all. 3’ of head is 3’ of head no matter how large the diameter.
Now increase the diameter of the pipe and you will decrease the max head even though the friction is less simply because gravity has a much more significant effect on the water than the friction.
No it wont
[quote=“Marchingbandjs, post:7, topic:2433”]
How would you increase the diameter of the return pipe, and still have a seal between the pump and piping…[/quote]
with couplings and reducers. any HD will have them
No it wont
[s]really?
so if i take a MJ400 with a max head of 30" and adapt the 1/2" output to a 6" pvc pipe it will still pump the water 29"?
it wouldnt be the first time i was wrong, but if this is the case its definitely counterintuitive. like i said, hydrodynamics isnt exactly my strength![/s]
alright, im wrong >LOL<
I should really research my answers first like everyone else so i dont look like an idiot so often!! I guess thats what cut/paste is for!
Your right, if anything, the larger the diameter of the pipe the more net volume/minute. I guess ive seen it a million times where reducing the pipe reduced the amount of vertical distance possible that i assumed the opposite would be true, which it isnt! Playing around with a calculator its obvious just how much friction is a factor. At one point by increasing the output pipe diameter by a factor of 6 my net flow was almost doubled. Learn something new everyday.
So would it be wise to make the return pipe from my pump to be bigger…
Seems so yes.