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..... Interesting, because I have the Magnum 350 running right now sitting on top of my tank with a polisher cartridge, you don't have to manually prime these, just fill them to a certain point in the canister itself and the pump action does the priming itself. The same holds true if you put the pump down below the water line, it'll still not run correctly if it is dry when you turn it on unless the water level in the canister is above that self-priming line.

Exactly my point. They are unable to "suck" enough water to fill themselves up, SO, you have to fill them up with water, prior to turning them on. If it's filled 3/4 of the way, it won't work properly, because they "push" water better than they "pull" water. For this reason, they never fill up. They fill to the level they've always been at, because there's not enough force, from the water coming in, to expel the air pocket, and replace it with water. Consider how much water these are supposed to turn over, 350 gph. If it were 3/4 full and able to "suck" don't you think it'd fill the rest of the way? They don't because they're unable to "suck." Once full, they will push 350 ghp, and remain full, because water is naturally replaced, by way of a natural vacuum, as water is pushed out of the canister. The reason they work better, when below the water line, is because they fill up with water, through gravity. This is how they are primed.
 
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I see what you are saying. I feed the skimmer with a mag 5. Everyone who I have talked to before and after I got this skimmer says I have no problem with what I am running thru the sump. It may be a waste of energy, but it is sure making my corals happy.

So you have to ask yourself is it the clean skimmed water or the extra flow the pump is producing that is making your corals happy?


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In your case Charlie, you're getting extra flow from your sump return so there is another reason besides filtration for the sump flow rate exceeding the processing capacity of the skimmer. Most people would probably say that it's not ideal to try and gain water flow in the display from a sump return (it should be only an added bonus, or an unintentional benefit to phrase it differently). If you were trying for more efficiency in the system, you could use a much smaller return pump sized to match the feed pump of a single-pass skimmer (again, not a recirculating design). If you gain a majority of the flow in your tank from this large sump return pump then you'd of course have to get powerheads or something to make up for the loss, so it's not really worth changing everything after it's already set up. On a brand new system however, it's a good thing to take into consideration :)
 
Exactly my point. They are unable to "suck" enough water to fill themselves up, SO, you have to fill them up with water, prior to turning them on. If it's filled 3/4 of the way, it won't work properly, because they "push" water better than they "pull" water. For this reason, they never fill up. They fill to the level they've always been at, because there's not enough force, from the water coming in, to expel the air pocket, and replace it with water. Consider how much water these are supposed to turn over, 350 gph. If it were 3/4 full and able to "suck" don't you think it'd fill the rest of the way? They don't because they're unable to "suck." Once full, they will push 350 ghp, and remain full, because water is naturally replaced, by way of a natural vacuum, as water is pushed out of the canister.

no no no, you said they do not suck, not that they suck at sucking when not primed properly or do not suck if they are not primed. there is a HUGE difference in your two statements.

it is almost as if you are doing a back petal.


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So you have to ask yourself is it the clean skimmed water or the extra flow the pump is producing that is making your corals happy?


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If I was to ask myself that, I would have quit the hobby way before this post ever started. I think we are trying to outthink ourselves here. If the critters are happy and growing, am I doing something wrong for having to much flow thru my sump, or that my skimmer may not be working as efficiently as it could???????
 
And I stand behind my statement. Pumps are designed to PUSH water, not SUCK water. There are a few types of pumps, specifically designed to suck water, called Suction Pumps,...but the majority of pumps are designed to PUSH water.

No back peddling needed.

BTW...Suction Pumps use A LOT more electricity than any pump we'd ever consider using on our aquariums.

no no no, you said they do not suck, not that they suck at sucking when not primed. there is a HUGE difference in your two statements.

it is almost as if you are doing a back petal.


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In your case Charlie, you're getting extra flow from your sump return so there is another reason besides filtration for the sump flow rate exceeding the processing capacity of the skimmer. Most people would probably say that it's not ideal to try and gain water flow in the display from a sump return (it should be only an added bonus, or an unintentional benefit to phrase it differently). If you were trying for more efficiency in the system, you could use a much smaller return pump sized to match the feed pump of a single-pass skimmer (again, not a recirculating design). If you gain a majority of the flow in your tank from this large sump return pump then you'd of course have to get powerheads or something to make up for the loss, so it's not really worth changing everything after it's already set up. On a brand new system however, it's a good thing to take into consideration :)

EXACTLY and since I choose to use a smaller return pump I need to produce more flow in my tank itself such as Power heads, and or closed loop.


Thank you for helping me hit 1600 posts. I feel like a king now, all this without spamming for post count!
 
Exactly my point. They are unable to "suck" enough water to fill themselves up, SO, you have to fill them up with water, prior to turning them on. If it's filled 3/4 of the way, it won't work properly, because they "push" water better than they "pull" water. For this reason, they never fill up. They fill to the level they've always been at, because there's not enough force, from the water coming in, to expel the air pocket, and replace it with water. Consider how much water these are supposed to turn over, 350 gph. If it were 3/4 full and able to "suck" don't you think it'd fill the rest of the way? They don't because they're unable to "suck." Once full, they will push 350 ghp, and remain full, because water is naturally replaced, by way of a natural vacuum, as water is pushed out of the canister. The reason they work better, when below the water line, is because they fill up with water, through gravity. This is how they are primed.
You are not being fair with your evaluation, if you remove water from a tank you produce flow regardless if you put it back or not, a reverse carlson has no water being put into the tank it simply moves it and causes flow, a bicycle pump will pull water from a tank and push water back in if submerged , a positive displacement pump will self prime, my car has 465hp to the rear wheels but it doesn't go anywhere till I take it off the hoist.

What's is the point?
 
In your case Charlie, you're getting extra flow from your sump return so there is another reason besides filtration for the sump flow rate exceeding the processing capacity of the skimmer. Most people would probably say that it's not ideal to try and gain water flow in the display from a sump return (it should be only an added bonus, or an unintentional benefit to phrase it differently). If you were trying for more efficiency in the system, you could use a much smaller return pump sized to match the feed pump of a single-pass skimmer (again, not a recirculating design). If you gain a majority of the flow in your tank from this large sump return pump then you'd of course have to get powerheads or something to make up for the loss, so it's not really worth changing everything after it's already set up. On a brand new system however, it's a good thing to take into consideration :)

Damn, you answered my post before I posted, god how good are you.:rolleyes:
 
And I stand behind my statement. Pumps are designed to PUSH water, not SUCK water. There are a few types of pumps, specifically designed to suck water, called Suction Pumps,...but the majority of pumps are designed to PUSH water.

No back peddling needed.

That is it I am suing Spokane Pump for false advertising based on your statements.

Really Pumps are designed to pump from one location to another. the action of pumping is sucking and pushing.

If you do not have something sucking or pulling your source to the impeller so it can be pushed or moved to the new location you do not have a pump. it is the old suck and push affect.
 
I admit that the Magnum canister example is a bad choice to show that a pump can indeed draw water, but using the priming process to disprove it is just as bad. All of the fluid material pumps I've used have to be primed in some way, because they're designed to pump liquids rather than air. If you have air gaps in a line intended for fluids, then the pump won't work, so in that sense they all have to be primed, it doesn't mean that they do not "suck" water. Use my example and the one Salty mentioned about above-ground well pumps, or irrigation pumps, these have to draw the water upwards, which I don't think you dispute since you specifically brought up a vaccum effect in the water lines. For the "vaccum" to work, there has to be differential pressure on each side of the device (the impeller or one side of the prop "blade" in this case) which causes the pump to both "suck" in water and "push" it out the other side. The exact same thing can be seen in an airplane wing. Differential pressure on the aerofoil shape makes the air flow more slowly across one side than the other (can't recall offhand if it was top or bottom that had faster flow *blush*), resulting in lift force. Differently stated and simplified, the air is "sucking" on the airplane wing and pulling it upwards.
 
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You are not being fair with your evaluation, if you remove water from a tank you produce flow regardless if you put it back or not, a reverse carlson has no water being put into the tank it simply moves it and causes flow, a bicycle pump will pull water from a tank and push water back in if submerged , a positive displacement pump will self prime, my car has 465hp to the rear wheels but it doesn't go anywhere till I take it off the hoist.

What's is the point?

you have a very fast car and his statement is utterly wrong?!?!?!
 
Your examples don't actually work. A Magnum 350 canister filter would NOT work unless you primed it. This is because they PUSH, not PULL, water. As they push water out, water is naturally replaced, by vacuum. Now, if you set that same Magnum 350 canister filter, on top of a tank, EMPTY, and turned it on, it'd never work....it'd just burn up the motor. The reason it wouldn't work is because they don't suck, so can't fill themselves up. They need to already be full, in order to have water to push out.

But once primed they do suck enough to provide flow

Your well pump examples also don't work. Well pumps, more precisely called "Jet Pumps," are placed DOWN IN THE WELL, and PUSH water up and out of the well.

Actually Jet pumps function my pumping water into the well through a venturi, like a penductor/eductor and suck water through the head end and push it back to the pump above ground where it is stored or used.

There are a few pumps that are able to suck, but aren't designed to. They also don't suck near as well as they push, since they were designed to push.

Of course they were designed to suck, it's called self priming. I will agree they blow better than they suck as far as making flow.

On an older topic...GPH of water is GPH of water, no matter how you look at it. If a pump is rated at 3000 gph of water, it's pushing 3000 gph of water, as long as it's rated correctly. If an impeller powerhead is rated at 3000 gph of water, it's also pushing 3000 gph of water, also, as long as it's rated correctly.

We are not arguing about sucking, we are saying that the result of a pump pumping it causes flow at it's input.
 
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