So I have a question, I don't have a sump. But I get this question asked frequently at my work. How do you determine what size pump you need in a refugium/sump? And is it different for saltwater and freshwater?
HELP: determine pump size for sump/refugium
- Thread starter Captain tank
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A pump is determined by how many times you want to turn the tank over. Say you have a 100g tank and want 10x turn over you would need a pump that has 1,000gph output after calculating head loss (the amount of gph you lose pumping from the bottom of the stand up into the tank.) Freshwater guys normally go for 4-10x turn over depending on how much current their tank inhabitants will handle. I'm not a salt guy but I know their flow rates will differ if they have a fish only tank, coral only, or a mix of the two. I do believe that their averages for flow rates are higher however.
The size of your pump is determined by your overflow. You can't pump more water out of your sump than your overflow is delivering.
Well duh! With proper planning the appropriate overflow can be purchased/assembled once you have determine how much flow you need/want for a setup. Flow rates should be a high priority on the "I want another tank" checklist. Never be afraid of adding an overflow.
Joe hit the main point. I'm assuming most people will have drilled tanks who ask this question so sizing the pump to the overflow us ideal, then after you calculate the flow through the overflow aquire a pump that can handle the intake.
Just a question not a statement.
Is it the overflow or the plumbing/bulkheads within the overflow that dictates gph ?
Or both ?
Is it the overflow or the plumbing/bulkheads within the overflow that dictates gph ?
Or both ?
Both. The weirs on the overflow will only allow water up to a certain rate. Sometimes, people have to start removing teeth on the weir to get high enough flow into the weir.
And HoB overflows have a flow rate, too--you already know that, though.
And HoB overflows have a flow rate, too--you already know that, though.
On a side note. I think the slower the better to a extent (use common sense no nasty film in sump). This gives the media time to do it's job. Your sump pump shouldn't be your primary water circulation. That's what powerheads are for. I have 300 gallon tank, 120gallon sump with a 900 GPH return pump. Works perfect...... People seem to get carried away with return pumps. Does nothing but waist electricity.
Another consideration for pump size, is the kind of fish you keep.
If you keep fish that live in slow moving environments like lakes or oxbows, discus or angels come to mind, a slower flow pump might be sufficient.
If you keep rheophillic species like Theraps or Retroculus cichlids you might want a much higher flow. I've kept a number of these cichlids, and use 2000+gph hour rates in their tanks, and beyond the extra oxygen, it seems to reduce aggressive tendencies. When I tried keeping them at what might be considered normal aquarium flow rates, aggression became excessive. Higher flows also helped with Maskaheros, and even some Vieja/Paratheraps and Astatheros types.
Or if you keep species that live in the counter current zones where currents clash, or waterfalls hit, such as African Tiger fish or certain species of wolf fish, you might want even more excessive flows aimed to crash together.
If you keep fish that live in slow moving environments like lakes or oxbows, discus or angels come to mind, a slower flow pump might be sufficient.
If you keep rheophillic species like Theraps or Retroculus cichlids you might want a much higher flow. I've kept a number of these cichlids, and use 2000+gph hour rates in their tanks, and beyond the extra oxygen, it seems to reduce aggressive tendencies. When I tried keeping them at what might be considered normal aquarium flow rates, aggression became excessive. Higher flows also helped with Maskaheros, and even some Vieja/Paratheraps and Astatheros types.
Or if you keep species that live in the counter current zones where currents clash, or waterfalls hit, such as African Tiger fish or certain species of wolf fish, you might want even more excessive flows aimed to crash together.
