Canister filtering a sump

[tthanatoss]

Well one pump 1 return right. So yea the single return is what you need.

 

[Bassinkorea]

Well one pump 1 return right. So yea the single return is what you need.

Cool. Any ideas about what sizes return pump would be ideal for a 1" return bulkhead and still good enough to filter a 280gal tank sufficiantly with enough turnovers per hour (3~5)?? I wouldn't want to over pressurise the bulkhead, hoses and pump.
I may have to drill slightly bigger holes in my spray bar, but that's a simple job.

 

[Toby_H]

Well from the little I know about pumps anything that has a 1" line is going to be a pretty big pump. Most of what I've looked at here can push out 1000g plus an hour through a garden hose. But I'm curious to see where your thread is going because I'm coming up on the same decisions with my own build and I have about as much experience with this as you do.

The 1” holes being discussed are the drain holes… the return line is separate and can easily be a different diameter…

dident realise you had 2 already.
but i have 3 as my sump return and they just keep up nice with a 3000 lph pump.
i ran 2 and it was a real pain because they did not keep up untill they started a syphon then they drained the sump quickly, then stopped. then the sump filled again till the syphon started then it drained again. a real pain when its sat in the livingroom next to you.
your overflow pipes need to keep up without becoming a syhon, or it will fill up then drain, fill up then drain and so on.
by syhon i mean when the pressure is enough to clear all the air from the pipe and drain. untill all the air clears from the pipe no over flow will flow at the rate you can FORCE water threw it with a pump.

Per Dictionary.com

Siphon - 1. a tube or conduit bent into legs of unequal length, for use in drawing a liquid from one container into another on a lower level by placing the shorter leg into the container above and the longer leg into the one below, the liquid being forced up the shorter leg and into the longer one by the pressure of the atmosphere.

While I understand what you are describing, including the word “siphon” to describe it is misleading as you are not describing a siphon

What you are describing is simply: When the water rises above the top of the intake (which is on the back wall) and then the air clears the pipe going to the sump allowing the water to move into the sump much much faster, due to not having the displacement of air slowing it down.

Out of my tank build, the filtering system is my weak point and I obviously didn't plan correctly for it. I could add an overflow, but I just didn't want to have PVC pipes visible inside the tank.

I completely agree with adding additional drain holes…

I also suggest you consider having the pipe from the hole come into the tank at the top of the back wall… split at a “T” fitting… then have a pipe going down so that the drain collects water from the bottom of the tank where the waste is at as opposed to the top of the tank where the water is already the cleanest… The “T” will prevent a siphon from starting and allowing the tank to drain if the pump is turned off.

Get a little creative with some Styrofoam and concrete to hide additional drains and piping if you choose to take my above suggestion…

I've been trying to do some research on flow rates vs pipe size and the math is beyond me but from what I've learned so far I think the guys are right and you are going to need a bigger overflow or a second one. Your tank is 280g, right? and the turnover should be a least 3 times per hour, more is better. That's alot of water. I think you should be looking a drilling another hole and adding a third bulkhead.

I’m not sure exactly what you are planning… But the author of this thread has his drain holes drilled into the back of his tank, as opposed to the bottom (which is more common). The flow rates between these two types of holes will be different…

I have seen charts suggesting typical flow rates for different diameter overflows, which were in regards to holes drilled in the bottom with standpipes I believe… although I do not have the links saved for reference…

Would you think a single 1" return bulkhead be big enough??

More than enough… to the point it’s size may work against you…

The pump is being forced to lift the weight of the water in the pipe… so the larger the diameter of the return pipe, the heavier the water in it will be… therefore the more restriction the weight of water will put on the pipe… thus reducing the pumps flow rate…

Reducing the diameter past a certain point will also work against you causing excess restriction… Finding the balance point between the two is key…

Since the pump will be designed with a certain sized output diameter, the restriction from using this size is put on the pump regardless… therefore I suggest you continue to use whatever size output the pump is designed with…

Cool. Any ideas about what sizes return pump would be ideal for a 1" return bulkhead and still good enough to filter a 280gal tank sufficiantly with enough turnovers per hour (3~5)?? I wouldn't want to over pressurise the bulkhead, hoses and pump.
I may have to drill slightly bigger holes in my spray bar, but that's a simple job.

I personally suggest you use all of your bulkheads for drains… and run your returns over the top edge of the tank. Since you have drains drilled in the back, this tank cannot sit flush to a wall, therefore you should be able to run return pipes up the back of the tank without any ill effect. Provided you have some sort of canopy, these pipes will not be visible. Once back in the tank spray bars are great ways to “secretly” place a return line…

The more drain holes you have the more flow you can put through the sump. You do not need to use the max flow rate… and I would rather the flow rate be determined by my choice as opposed to the systems limitations.

Until you know exactly how many drains you are going to use… No one can suggest a pump size… Once you do determine the number of Drains, I would then search for a chart from a reliable source as here you will just get our speculations…

 

[Bassinkorea]

Wow nc_nutcase, thanks for the great info and thanks for taking the time to type all that info!!

 

[joey02]

I have my plywood tank also drilled with two 1" bulkheads installed in the wall of the tank as the overflow. They have strainers on them, but they reduce the flow, so I removed them. I only have a mag-drive 7 for the return and it is a bit too strong, so i divert some of the flow back threw the filter. I estimate that i am only getting around 200gph out of each bulkhead without the strainers. On that size tank i would go with a couple 2" bulkheads. where ever you place the bulk heads on the side of the tank is where your water level will be, you'll also want to size the bulkheads bigger than the return pump.

 

[sharp tooth]

nc_nutcase

we arnt all so good with words. picking such a small thing to correct some one on is abit sad. just continue to make your self look clever.

im sure ppl got the drift of what i was on about.

 

[tthanatoss]

You've started a good thread here Bass. I've learned alot.

 

[Bassinkorea]

Glad I was able to help, even though I know nothing

I'm thinking about changing the title of this thread to "Bassinkorea's filter thread" since I have too many questions

 

[Pharaoh]

I'm seeing about 600gph max for a 1" pipe. I would go with two drains.

 

[Bassinkorea]

That's good info Pharaoh, thanks.