Pumps and pipe sizes lil help please

[GrossGraphix]

I know there is a thread for the flow rates. http://www.monsterfishkeepers.com/forums/showthread.php?t=205645
I have two RIO26HF rated for 4ft head @ 1350gph and 6ft @ 1140gph. From the pumps to where they go in tank it is 4' 10" with one 90 degree and one check valve on each.

Question 1: So that should give me abouts 1455gph at that head correct?

I have 1.5" return pipes going by charts in the thread should be 1350gph vertical siphon flow.

OK here is my problem i have a horizontal pipe across my sump with 3/8 in holes in it 4 for each return (two returns two pumps) I flow way more than the pumps can pump. Goin by my figures i should be pumping more than i am returning.

Question 2: Should i drill smaller holes and if so how many and what size do ya think???

Please help someone.

 

[BadOleRoss]

I am confused! If you are using a sump, the pump should feed water to the tank which will then overflow into the sump. Are you saying you have 2-1.5" bulkheads going to spraybars going across your sump? And the spraybars have 3/8" holes drilled in them?
I am using the same pumps on a 315G tank. I had 2-1.5" bulkheads going into 1.5" PVC straight to my sump and the 2 bulkheads could only keep up with 1 of the pumps. I had to use the 2nd pump to recirculate water within the sump until I fixed the problem. I ended up installing 2 overflow boxes which each contained 2-1.5" drains that go into a 3" pipe to the sump. That keeps up with my 2 pumps nicely.

 

[Toby_H]

I have two RIO26HF rated for 4ft head @ 1350gph and 6ft @ 1140gph. From the pumps to where they go in tank it is 4' 10" with one 90 degree and one check valve on each.

So you have 4' 10" of head plus the resistance of a 90* bend... so essentially 5' of head...

Question 1: So that should give me abouts 1455gph at that head correct?

No... I averaging the 4' head and the 6' head we get 1245 gph...

Most pumps offer a graph with a curve allowing you to estimate a bit closer. Without such a graph, averaging is about all we can do.

The number you stated suggests at 4' 10" head with a 90* you have more flow than at 4' head without a 90*... I think you fudged the wrong way...

I have 1.5" return pipes going by charts in the thread should be 1350gph vertical siphon flow.

OK here is my problem i have a horizontal pipe across my sump with 3/8 in holes in it 4 for each return (two returns two pumps) I flow way more than the pumps can pump. Goin by my figures i should be pumping more than i am returning.

You could do the math to calculate how much water would flow out of the horizontal pipe at the sump... Or you could just make sure you have enough holes to not restrict the flow.

If you choose to do the math I'm willing to bet you miscalculate some minor detail that throws your conclusion off enough to make the calculations not worth doing... Despite being a math guy myself, I'd estimate at this point.

Question 2: Should i drill smaller holes and if so how many and what size do ya think???

I'd start with 8 3/8" holes in each... then put it to the test and adjust from there... but that's simply my estimation.

 

[Toby_H]

Also... if your intake picks up a piece of waste and clogs one of your holes, you will be in really big trouble... Is the horizontal pipe at the sump really necessary?

 

[GrossGraphix]

So you have 4' 10" of head plus the resistance of a 90* bend... so essentially 5' of head...





No... I averaging the 4' head and the 6' head we get 1245 gph...

Most pumps offer a graph with a curve allowing you to estimate a bit closer. Without such a graph, averaging is about all we can do.

The number you stated suggests at 4' 10" head with a 90* you have more flow than at 4' head without a 90*... I think you fudged the wrong way...




You could do the math to calculate how much water would flow out of the horizontal pipe at the sump... Or you could just make sure you have enough holes to not restrict the flow.

If you choose to do the math I'm willing to bet you miscalculate some minor detail that throws your conclusion off enough to make the calculations not worth doing... Despite being a math guy myself, I'd estimate at this point.




I'd start with 8 3/8" holes in each... then put it to the test and adjust from there... but that's simply my estimation.

Ok correct i did do the math wrong your right abouts 1245gph. So then i need enought holes in the spray bar to be some where between 1.25" and 1.5" to equal out the pumps correct.
1.25 = 937.5gph and 1.5" = 1350gph

Far as having a spray bar i guess no i do not need it but i figured a open 1.5" would of been to much flow. Which as of trying it. It is go much flow with a couple of 3/8 holes in it. Just figured it would just help distribute the flow over the bio better.

Do ya think i can just ditch the spray bar and just use a 90degree into the sump without it making the water level in the tank jump up and down when and if it would start to siphon?

I guess i can just cut off the pipe and just fit a 90 on without glueing it and see if that works for me.

 

[GrossGraphix]

was going to post pics but guess i cant figure out how to do that or im not allowed by the site

 

[GrossGraphix]

??

 

[Burnsie]

Your over flow / return should always be designed to flow more than your pumps. It will only flow at the same rate as your pumps.

Unless your not using an over flow, are taking the return from the bottom of the pump and trying to balence the flow by adjusting the holes in your sump's

You will never get that to work and will end up with a wet floor.

 

[Toby_H]

Your over flow / return should always be designed to flow more than your pumps. It will only flow at the same rate as your pumps.

If the overflow is capable of draining more water than the pumps deliver... then the overflow will suck air...

If the pumps deliver more water than the overflow will drain... the floor will get wet...

Ideally... you want them in a perfect balance...

Realisticly... you will want to play it on the safe side to prevent the worse of the two results (most of us consider a wet floor much worse than a loud intake).

In my opinion... equiping both the pump and the intake with ball valves gives us the most control to push our balance whicever way we feel makes it most effective for our goals.