Sumps are bad for reefkeeping

I think a behind-the-tank sump would be a great idea, for an INWALL, with a fishroom. The basement is such a waste of electricity.
 
I have a 40g with a 10g sump...no problems with bubbles...and I'm definitely avoiding with a 10 foot pole the whole nitrate arguement.

As far as the "behind the tank sump" idea goes, it's one I've been toying around with. I tried it on a nano just to see how it looked and worked. I have a two gallon tank that I placed a baffle a few inches away from the back wall. I drilled a few slits in the top right side for water to flow into the "sump", through a few more baffles, and is pumped a whole whopping 4" back up into the main display. I love the fact that this allows for only one lighting system and no chance of overflow. However, this IS only a pico tank...and does not fully model a real system. The reality of being able to stick lots of equipment behind a tank is just generally not feasible (unless you're not poor like me and have a closet behind your tank to hide equipment.)

Yes, it's interesting, but I think it's only for a limited group.
 
It sounds like you guys should shift this to the causes of Microbubbles and sources of and out to eliminate them before the start and how to and where to trap them.
 
<a href=showthread.php?s=&postid=10366343#post10366343 target=_blank>Originally posted</a> by RichConley
I think a behind-the-tank sump would be a great idea, for an INWALL, with a fishroom. The basement is such a waste of electricity.

why is the basement sump a waste of electricity?
 
Pretty sure he means it takes more electricity to pump water up to the next floor than it takes to pump it from the next room on the same level.
 
I have 1 refugium and 1 refugium/sump. All the bubbles produced from the drain is absorbed by the live rock and chaeto in the sump. I read this thread and got the impression that most of the posters never had problems with bubbles. It's simple: water and air mixes from the drain and creates bubbles. It's extremely common and IMO extremely easy to fix.

To the OP: what's your point and/or solution? "A behind (slightly over) the tank sump" - what does that mean, exactly? How is that different than an under the tank sump? A microbubble-free skimmer isn't a skimmer.
 
Last edited:
<a href=showthread.php?s=&postid=10377744#post10377744 target=_blank>Originally posted</a> by tperk9784
Pretty sure he means it takes more electricity to pump water up to the next floor than it takes to pump it from the next room on the same level.
If thats the case it's still wrong. If you have a pump in another room on same level and it has to go 25 ft (example) to get to the tank. Placing the same pump in the basement uses no more electricity. It's still the same pump, still the same load. It's not going to use more amps just because it has to got vertical over horizontal. The amps put out by the pump are the same regardless of which floor it's on.

There are tons of benefits to placing it in the basement. Beside lack of noise in the tank area. There is the added advantage of more room to work, larger sumps, the all to important coral grow out tank, the added bonus of having someplace to hide from the wife and kids. I'd really like to know myself why basement placement is a waste of money.
 
<a href=showthread.php?s=&postid=10378297#post10378297 target=_blank>Originally posted</a> by seattlerob
nasek718: it takes a bigger pump to create the same flow when comparing 0 ft to 25 ft. It's called head pressure I believe.

In other words, a return pump that is 1000gph at 0 ft head will be much less gph at 25 ft head. In fact, most pumps will have a maximum head pressure rating.

Take for example the Sequence Dart: http://www.premiumaquatics.com/Merc...ct_Code=SQ-REEFLO18-SW&Category_Code=Sequence

hth,
rob
I know that but if the pump is doing 1000gph @25 ft it's going to use the same amp's to run it regardless of if the head is pointed north, south, east, or west. It might work a little harder going vertical and that's only because of back pressure and gravity but if that is what it's was rated to do, it will do it. Now the same pump set under you tank w/ say 10 feet of head would produce a greater head but still the same amount of electricity. It can't decide on it's own to pull more electricity then it was designed to. The only thing that can be exceeded is the current flowing thru the gauge of wire it uses to supply the pump power or the circuit supporting it. That's my point. It's really to bad that pumps don't work like say car amps. They only use the power needed to move the speaker at the volume you set them. 1000 watt amp will not put out 1000 watts if the volume only requires 200 watts. Pumps run wide open.... (if you know of a pump with a variable electric current, please point me to it.)
 
nasek, I don't think you have a firm grasp of how centrifugal pumps operate. They are ALL variable electric current.

As head increases, output decreases. As output decreases, so does power usage.

We can plot this power usage vs output on a graph. We would call it a pump curve.

Each motor-impeller-volute combination has a "sweet spot" or BEP (Best operating point) where flow-per-watt is maximized. On either side of BEP flow-per-watt decreases.

That is all fine and dandy... but you are also missing another point.

Pump do WORK. They lift water. Water has weight and therefore takes energy to move. Moving water 100 vertical feet takes more energy than moving water 10 vertical feet. Either the pump does less work, or the water has less energy when it gets to the finish height. Because these are NOT positive displacement pump, we get a little bit of both.

The water at the 100' head has much less pressure at the nozzle exit than does the water at the 10' exit.

BUT DO NOT FORGET that 100W pump at 100' moves 10GPM and at 10' It moves 100GPM.

So we have
100W at 100' = 10 gallons = 10 Watts per gallon of water moved
100W at 10' = 100 Gallons or 1 Watt per gallon of water moved

That is ALL without the current changing :) I.E. an assumed linear relationship, not a curve.

For a real world numbers lesson, just look at a pump curve...

sequence-reefflo-dart-curve.jpg


Notice the CURVE showing the power consumption (variable is the term you used...)

GPH _ _HEAD _ WATTS _ GpW
0 _ _ _ 12 _ _ _110 _ _ _0
600 _ _11 _ _ _130 _ _ _4.6
1200 _ 10 _ _ _145 _ _ _8.3
1800 _ 08 _ _ _158 _ _ _11.4
2400 _ 06 _ _ _160 _ _ _15
3000 _ 03 _ _ _155 _ _ _19.4
3600 _ 00 _ _ _140 _ _ _25.7

I hope you can use this information to better understand the realationship to pump outout vs power consumed.

As you can VERY CLEARY see, it takes MUCH more power to provide the needed flow from a basement sump compared to a nearby sump.
 
Last edited:
<a href=showthread.php?s=&postid=10379101#post10379101 target=_blank>Originally posted</a> by BeanAnimal
nasek, I don't think you have a firm grasp of how centrifugal pumps operate. They are ALL veribale electric current.

As head increases, output decreases. As output decreases, so does power usage.

We can plot this power usage vs output on a graph. We would call it a pump curve.

Each motor-impeller-volute combination has a "sweet spot" or BEP (Best operationg point) where flow-per-watt is maximized. On either side of BEP flow-per-watt decreases.

That is all fine and dandy... but you are also missing another point.

Pump do WORK. They lift water. Water has weight and therefore takes energy to move. Moving water 100 vertical feet takes more energy than moving water 10 vertical feet. Either the pump does less work, or the water has less energy when it gets to the finish height. Becuase these are NOT positive displacement pump, we get a little bit of both.

The water at the 100' head has much less pressure at the nozzle exit than does the water at the 10' exit.

BUT DO NOT FORGET that 100W pump at 100' moves 10GPM and at 10' It moves 100GPM.

So we have
100W at 100' = 10 gallons = 10 Watts per gallon of water moved
100W at 10' = 100 Gallons or 1 Watt per gallon of water moved

That is ALL without the current changing :) I.E. an assumed linear relationship, not a curve.

For a real world numbers lesson, just look at a pump curve...

sequence-reefflo-dart-curve.jpg


Notice the CURVE showing the power consumption (variable is the term you used...)

GPH _ _HEAD _ WATTS _ GpW
0 _ _ _ 12 _ _ _110 _ _ _0
600 _ _11 _ _ _130 _ _ _4.6
1200 _ 10 _ _ _145 _ _ _8.3
1800 _ 08 _ _ _158 _ _ _11.4
2400 _ 06 _ _ _160 _ _ _15
3000 _ 03 _ _ _155 _ _ _19.4
3600 _ 00 _ _ _140 _ _ _25.7

I hope you can use this information to better understand the realationship to pump outout vs power consumed.
I stand corrected.
 
I am using a mag3600 running full out ( about 7 feet of head)
Are those variables not steady therefore the pump giving the same output and using the same watts?
If I decrease the output then I would expect the draw to be less?
That said I find it hard to see a difference in energy consumption whether the pump is pumping vertical then horizontally.?
I asking not stating here
 
<a href=showthread.php?s=&postid=10379161#post10379161 target=_blank>Originally posted</a> by BeanAnimal
:)

The day is wasted unless you learn something!

no the day is wasted unless you crawl away from Reef Central with at least 2 misconceptions clarified and humbled by the awesome knowledge of the experienced. LOL
 
"head" is a measure of the resistance to flow. This can be from gravity (vertical lift) or from resistance due to plumbing and other restrictions.

You can decrease the power consumption of the pump be restricting the output. You will however also restrict the output :) That likely means less flow per watt consumed.

The question then becomes simple. If I can get away with LOWER flow, then why don't I buy a smaller pump that will operate at better efficiency?

You can do this by comparing pump curves of pumps in the range of flows you are contemplating.

Study the pump curve above and notice how the relationship is not linear.
 
Capn...

It is not so much experience. It is a willingness to learn and understand. I learn every day simply by paying attention to the world around me :) I am humbled daily in one way or another.
 
<a href=showthread.php?s=&postid=10379236#post10379236 target=_blank>Originally posted</a> by BeanAnimal
Capn...

It is not so much experience. It is a willingness to learn and understand. I learn every day simply by paying attention to the world around me :) I am humbled daily in one way or another.

---and knowing how to learn---we just discussed this last night--the internet is one medium---there are text books, hands on observation and asking questions, visits to local fish stores(I always hang around in a few favorites and usually end up striking a conversation with another customer) visiting fellow reefers setups etc etc.
--its good to hear that the 'experienced ' are also humbled:)

I feel humbled and honoured that you are communicating with me in a forum for the advanced :)
 
<a href=showthread.php?s=&postid=10379220#post10379220 target=_blank>Originally posted</a> by BeanAnimal
"head" is a measure of the resistance to flow. This can be from gravity (vertical lift) or from resistance due to plumbing and other restrictions.

You can decrease the power consumption of the pump be restricting the output. You will however also restrict the output :) That likely means less flow per watt consumed.

The question then becomes simple. If I can get away with LOWER flow, then why don't I buy a smaller pump that will operate at better efficiency?

You can do this by comparing pump curves of pumps in the range of flows you are contemplating.

Study the pump curve above and notice how the relationship is not linear.

by jove I get it :)
It was just hard to comprehend because I associated the steady noise of the pump with its draw and output---but then I never slowed it down ---oh forget it---

lets just leave it at I get it :)
 
Back
Top