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

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It's too long since I took physics but I thought that the height would be equal. One is an actual rainbarrel, with faucet already installed:
http://www.rainbarrelstorage.com/good-ideas-rain-wizard-gallon-rain-barrel-green-rw40-p-7851.html
I paid a lot less than that but still more than a barrel should cost even though it comes with a faucet already installed. It filled up so fast that I figured I'd add another barrel to double the capacity. I took an old Rubbermaid plastic garbage can, installed a faucet near the bottom, used a Y adapter on each faucet, and a female-female hose to link the two barrels, leaving one tap available on each one for a hose. Both barrels are raised on cinderblocks to the same height.
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.
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do you have a lid on one but not the other?
Barrels set a different heights?
Harry K
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On Tue, 5 Jun 2012 06:42:58 -0700 (PDT), Harry K

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.
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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.
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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
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wrote:

Connecting hose is pretty cheap garden hose, maybe 3/4" outside diameter. There could be some narrowing because I cut off the male end and used a plastic female adapter.
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wrote:

Good point, but they're right next to each other so they're both at the same height off the ground.
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dgk wrote:

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

...
...
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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I was really puzzled because I would have bet that they'd end up the same height. Maybe they will equalize after some time.
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You have to make sure the ground itself is reeally level!!!
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On Tuesday, June 5, 2012 10:27:28 AM UTC-4, dgk wrote:

Nope, the level should have equalized fairly quickly. Speed only dependent on how fast the water could flow from barrel to barrel.
You are using the wrong point of reference for your measurement of height.
The water levels must be measured using the SAME point of reference.
I bet if you take an 8' bubble level, and suspend it over both barrels such that it is level, and measure from that level to the surface of the water in each barrel, the levels will be the same on both barrels.
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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
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On Tue, 5 Jun 2012 21:24:20 -0700 (PDT), Harry K

Maybe it's sort of an optical illusion. When I get home today I'm going to stick a ruler down each one and see just how high the water is.
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On Thu, 07 Jun 2012 10:42:07 -0500, Atila Iskander wrote:

... just not a 2x4 from HD, because theirs are usually banana-shaped :-)
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On Thu, 7 Jun 2012 16:23:49 +0000 (UTC), Jules Richardson

That's very funny. Well, not really funny when you're trying to get a straight piece.
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On Thu, 7 Jun 2012 10:42:07 -0500, "Atila Iskander"

OK if he uses a level instead of his "old eyes"
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This concept is taught in 3rd grade Physics. Some of you need to take a refresher class. Sheeeeeeeesh!
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On 6/5/2012 8:16 AM, dgk wrote:

http://www.rainbarrelstorage.com/good-ideas-rain-wizard-gallon-rain-barrel-green-rw40-p-7851.html
if they are not the same diameter, the levels will not be the same.
--
Steve Barker
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