Flow question

[baddfish]

For those with some hydrology knowledge...
Say I had one tank above another with a total water height of about 5 feet. If the upper tank was drilled and plumbed straight down into the bottom tank, would an overflow on the bottom tank still keep the pressure of 5 feet going to the sump?
If the full return went to the top tank, would the system work this way?

 

[14 gallon nanocube]

anything is possible with valves to control the flow.post pics sketches whatever.need pipe sizes to figure flow rates etc

 

[baddfish]

I'm working on some diagrams, but what I'm wondering is if the sump intake is a foot higher than the overflow of the bottom tank would the flow from the height of the top tank still push the overflow from the bottom tank a foot higher than its water level? Seems to me like it should work as one big tank.

 

[baddfish]

something like this...

 

[d2mini]

I'm not sure, but I would guess you would need to pump the water from the bottom tank to the sump.

 

[PRC]

If you switch the 2 display tanks around it will work. Use the tank that has the overflow box at the top, have it drain to the (drilled) tank, and the drilled tank goes to the sump.

If you try to use the overflow box on the 2nd tank, I think you're going to have issues with the syphon(because it looks like it's going against gravity) but the other tank that is drilled, doesn't use a syphon, it's just a drain in the bottom.

If you simply stacked them one on top of another with the sump at the bottom either configuration would work.

 

[baddfish]

I was hoping that wouldn't be the case. That would make balancing a pump in the sump and a pump in the bottom tank with the overflows pretty complicated.

 

[bojangles93]

Sorry to say that I do not think that will work the way you have it drawn out. I do not think that there would be enough pressure to push the water up a foot although you would have a lot of flow. IT is the pressure that would be required to push the water up to the third tank.

Also if you had an outage there would be a good chance at a flood I would think.

I would try to move the third tank to the lowest position if possible, then you would only need a return pump in there to run the system.

:twocents:

 

[14 gallon nanocube]

water will only flow up hill with the help of a pump.you cant fight gravity the only way your picture would work is if all tanks and sump were sealed and under pressure

 

[baddfish]

I wonder if the bottom tank's overflow was just a few inches higher than the sump water level would that give it enough fall to make the system work?

 

[baddfish]

water will only flow up hill with the help of a pump.you cant fight gravity the only way your picture would work is if all tanks and sump were sealed and under pressure

If you drop a piped drain 6 feet and run it back up 5 feet, you're still going to have pressure...i'm guessing because the bottom tank is an open container you don't retain the pressure of the total height of the two tanks.

 

[baddfish]

After doing a little research I think the best bet would be each tank having an overflow higher (at least by some degree) than the sump, and each tank having its own seperate return pump. The flow thru each tank would be determined by its own dedicated pump, and as long as each overflow can handle each pump's output. From what I understand, things would balance out in the sump the way a single tank does. The main concern would be making sure you have enough room in the sump for drainage from both tanks in the event power is shut off to both pumps.

 

[bojangles93]

Wouldnt you see evaproation in the two lower tanks, sticking with the theory that you only see evaporation in the return section?

 

[baddfish]

Both return pumps would be in the same area of the sump, after the bubble trap. I'm pretty sure evap would still only show up in that area...just two tanks worth instead of one.