pmrossetti
Active member
At 5' head Eheim gets 700gph which is fine. Sicce hasn't gotten good reviews. Impeller gets pitted after 6mos. And most pumps are over 100watts for descent flow. That's why I narrowed it to WB or Eheim.
Internal return pump with no restart issues?
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At 5' head Eheim gets 700gph which is fine. Sicce hasn't gotten good reviews. Impeller gets pitted after 6mos. And most pumps are over 100watts for descent flow. That's why I narrowed it to WB or Eheim.
pmrossetti
Active member
Are you absolutely sure of that?
Absolutely. Its fact and its physics. Water is pumped from the high level of the container. I can even see this in my topoff container which is a 44G Brute 33" tall. When it is full, I get a very strong stream of topoff. When it is almost empty, barely a drip. Pump is in the same place in both cases.
pmrossetti
Active member
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Verticle travel is verticle travel. If the pump is sitting at the bottom of a 4 foot tall sump and the pump is 6" tall then you would have to pump 3.5' to reach the top of the sump correct? Now lets say we plumbed this same pump externally at the bottom of the sump. It would still take 3.5' to reach the top of that same 4' sump would it not. The water does not help the pump to push up infact as you go deeper the water pressure increases. In 4' or 1' it should make no difference either here or there.
pmrossetti
Active member
that makes sense, too.
You are pumping against the atmospheric pressure of 14.7 PSI. There is also 14.7PSI pushing down on the water level of the sump. The level in the sump and the equivalent level in that length of plumbing (almost) cancel each other out. You do have the friction loss of that length of plumbing so you lose a little.
pmrossetti
Active member
So if you have a tank 10' tall and a sump 10' tall full of water there's 0 head?
What if the pump is on a 10' stand? Is it still 0 just like it was at the bottom?
Midnightsun
New member
If the sump level was Higher than the aquarium level you would output more than the advertised output. 4' + a few inches because of plumbing is correct on your system. Read this to understand head pressure. http://www.mcnallyinstitute.com/07-html/7-01.html
pmrossetti
Active member
That's a little above me.sorry
what about my previous question about the pump on the bottom and then on a stand? Same head?
Here is a good link, specific to setting up aquariums, on the subject. http://www.aquariumpros.com/articles/headpress.shtml
I can see that the water weight in the 44g brute is probably helping to force more water into the top off pump but not at a 100% increase.
I can see that the water weight in the 44g brute is probably helping to force more water into the top off pump but not at a 100% increase.
pmrossetti
Active member
According to this, you're correct.
Which means my original est. of 7' was right!!!!:eek2:
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Going by your link subtracting the 9"-10" of water above the impeller we would still have 26"-27" to the tank and then 2' more to the top of the tank where it will get tee'd off so you need to add 1' there. Then there will be 2 90* elbows after that that will count as 1' each or 2' total. We are now at 6' 2"-3".
That link explains why the sump level does make a difference and is subtracted from the pumping height.
Just as the water weight in a sump forces the water into the return pump. As I posted, its not quite equal because you still have the friction loss in that length of plumbing.
But as your brute proves this effect is much less at the 1' mark and below. But like I posted above, even when we subtract the sumps water we still end up at a tad over 6' not 4'.
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