Re: Inlet tube height

[Stan]

Thats odd. All of mine flow the same regardless of the length of the input
tube. Remember the flow adjustment lever at the back should be all the way
up.

If the water level decreases, so does the flow.


"D&M" > wrote in message
...
> Is there any specific reason besides catching free floating low level
debree
> that it's recommended that the inlet tube be 1 1/2-2" from the tank
bottom?
>
> Only asking as my emperor flows fast when only 8" into the water, slows to
a
> trickle at the full depth of the tank. Just curious if there was a greater
> benefit other than catching debree that low in the tank.
>
> Cheers
>
>

[D&M]

I'd assumed something of the same, in fact, thought the deeper the tank, the
higher the water pressure would be lower in the tank, theoretically
increasing the amount of flow. Both the Fluval and Emperor tubes are about
21-22" into the water, the fluval outpowers it now in flow, and is only half
the rating. I'm wondering if it's a possible design flaw in the size of the
inlet tube, it's a pretty odd and large shaped tube. If I remove the
extension, so it's only retrieving water about 8" down, it flows hard enough
to blow the fish right across the tank. Or the inevitable, I got a faulty
unit. Either way, even operating at 1/2 power, it still works fine, just not
at it's full potential IMO.

Cheers

"Stan" > wrote in message
...
> Thats odd. All of mine flow the same regardless of the length of the
input
> tube. Remember the flow adjustment lever at the back should be all the
way
> up.
>
> If the water level decreases, so does the flow.
>
>
> "D&M" > wrote in message
> ...
> > Is there any specific reason besides catching free floating low level
> debree
> > that it's recommended that the inlet tube be 1 1/2-2" from the tank
> bottom?
> >
> > Only asking as my emperor flows fast when only 8" into the water, slows
to
> a
> > trickle at the full depth of the tank. Just curious if there was a
greater
> > benefit other than catching debree that low in the tank.
> >
> > Cheers
> >
> >
>
>

[SG]

In article >, D&M wrote:
>I'd assumed something of the same, in fact, thought the deeper the tank, the
>higher the water pressure would be lower in the tank, theoretically
>increasing the amount of flow.

The water pressure is canceled out exactly by the water in the tube.

It sould like the possibly deffective extender tube is significantly
restricting the flow.

[Dennis Fox]

SG wrote:
> In article >, D&M wrote:
>
>>I'd assumed something of the same, in fact, thought the deeper the tank, the
>>higher the water pressure would be lower in the tank, theoretically
>>increasing the amount of flow.
>
>
> The water pressure is canceled out exactly by the water in the tube.
>
> It sould like the possibly deffective extender tube is significantly
> restricting the flow.

That is correct. The water pressure depends _only_ on height of water
above the point of interest; thus water pressure is the same inside and
outside the inlet tube at any point you want to measure it.

On the other hand, the resistance to flow through a pipe is a complex
relationship of both the inner diameter of the pipe and the length of
the pipe. The smaller the pipe's diamater, the more resistance. The
longer the pipe, the more resistance.

So to have good flow with the inlet tube extended near the bottom of a
tall tank, you want it to be as large in inner diameter as possible.

I was a physicist in a former (professional) life.

HTH,
Dennis