Two barrels, linked at bottom by a hose, with different water heights?

do you have a lid on one but not the other?

Barrels set a different heights?

Harry K

No.

They will reach equal height -> with respect to a common reference point.

This is assuming there is no air in the connecting hose, or the connecting hose does not rise higher at any point in it's run between barrels than the initial water level in either barrel.

The cross-sectional area of the barrels will not play any role in this.

On 6/5/2012 8:16 AM, dgk wrote: ...

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Eventually, it should definitely reach the same level. Since the one only I presume is connected to the downspout the differential filling will be pronounced in its favor and apparently there's sufficient pressure drop/friction loss to add a significant head on the one side relative to the other. But, that's a dynamic loss that eventually gravity equal pressure external should overcome and the levels will equalize. Unless there's a cover that's building a pressure dome over one side or other interfering issue.

There's a wikipedia article on water columns I just looked at to refer you to altho I forgot to copy the link, sorry, it wasn't hard to find...

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The original is mostly sealed but has two screened areas. The Rubbermaid has no top but I have sealed it with a screen and wooden planks to keep stray critters from falling in and drowning. Air pressure is unlikely to be a factor.

Both are on a couple of cinderblocks so the base is at the same height off the ground. The Rubbermaid is about 8" taller.

I was really puzzled because I would have bet that they'd end up the same height. Maybe they will equalize after some time.

Nope, the hose dips between the two, below the bottom of the barrels. I guess there could be some air in the hose, but one of my checks was to turn off the faucet on the rubbermaid and leave both valves open on the splitter. Water came out so it was clearly still coming from the first barrel. I'm hoping that it will equalize when I'm not watching it.

if they are not the same diameter, the levels will not be the same.

strike that. I am thinking of something else. (don't know what).

Same thing I'm thinking of, most likely. Something to do with gravity & such. We can't both be wrong, can we?

Jim

Water seeks it's own level. The size or shape of the two barrels/buckets doesn't make any difference-----so under normal circumstances the water levels would be at the same height ( the volume of water in each container can be significantly different). One factor that would result in different heights would be if the tops of one of them (or both) are sealed-air tight. Another would be if the connection between the containers is restricted limiting the flow between them--in this case the levels would eventually be equal so long as there is a flow between the containers. If the full container has it's top sealed than the amount of water leaving it would be very small --think finger on the end of a straw Again, if the top is not completely air tight then there will be a transfer of water but at a very slow rate. Overall, the water levels between the two containers would be governed by a force balance---Look up how a manometer works. MLD

dgk,

This seems to avoid Harry K's point. If I put a barrel on top of 2 cinderblocks at the bottom of a hill and then put a barrel on top of 2 cinderblocks at the top of the very same hill, the fact that each barrel is only 2 cinderblocks up from the ground is not especially relevant. The water columns should be the same height from the Earth's center of mass (or whatever) when they equalize. I'm having a hard time believing that the resistance through the various faucets would be enough to slow the equalization markedly.

Unless there is a strange restriction the levels WILL be equal in both barrels.

What is the interior diameter of the connecting hose?

A water level is a hose, with water, and a vertical guage at each end of the hose, used for leveling or determining the level of a surface. I have one 75' long, with a hose of 1/2" interior diameter hose.

Your connecting hose can not have an interior diameter of 3/8" or less, or, like a water level, it will not work properly by leveling itself off. Air pockets are most likely to get trapped and affect a water level when using a tube or hose of 3/8" or less (in interior diameter), also, and that is why water level hoses must have an interior diameter of greater than 3/8". Osmotic pressure!!!

Sonny

Yes they will. One could be an inch in diameter, and the other 6 feet, and the level in both will be the same if they are connected. Note, it will be the LEVEL, not the distance from either the top or bottom of the container.

The hose from the bottom will be full to the level of the water in the barrel if the valve is left open and the end of the hose is higher than the water level in the barrel.

How different are the water levels?

And how are you measuring it? The barrels are some distance apart, probably one's taller than the other; you sure it's not a trick of the eye?

Chip C Toronto

From what I remember of school, the water SHOULD reach the same height, in both barrels. The fact it's not, well, who can tell? Do you have the barrels on a slope, so one is lower than the other?

Christopher A. Young Learn more about Jesus

Once I turned on the connecting hose, the water did flow from the original one to the Rubbermaid, but stopped before the water heights equalized. I checked the connection but there was no blockage. I walked away puzzled.

It rained some yesterday, and both barrels are much fuller, but again, the water heights are not identical.

So I guess the height of water in two dissimilar barrels, connected by a hose, will not be the same but will vary depending on the diameter or width of the barrels? Not what I remember, but that wouldn't be the first time.

Any chance there might be some kind of anti-backup valve built into the either of these faucets? Unless they're connected with aquarium tubing, they should have equalized quickly and a little air in the hose would not have mattered. How much of a difference is there? Are we talking millimeters or inches?

You have to make sure the ground itself is reeally level!!!

One way they could differ but it would take laboratory grade/accurate instuments to see it.

One barrel in the sun, the other in the shade.

That is another way to screw up using a water level. Because the water level uses very small diameter tubing, the effect is enought to be noticeable.

Harry K

Harry K