ReachTheSky
07/05/2013, 11:47 AM
Looking for a return pump? Don't know which one to buy but you're confused as heck because there's so many? Well, hopefully this will help you narrow it down. :wavehand:
The first thing we need to look at are turnover rates. A turnover rate is your total water volume multiplied by X. A 100g system with a 3x turnover rate has 300gph of waterflow. With FOWLR systems, 5-10x will be enough, but sometimes you might want more so particles don't settle as easily. For reef tanks, you will need up to 30x and even more for SPS systems.
Fortunately we have powerheads and closed loop systems that handle most of the frontline work in terms of waterflow. This will make the return pumps job much easier. It still needs to be sized accordingly though!
The general recommendation for return pumps is one with a 3-5x turnover rate. You don't have to match this exactly but it gives you a good idea of what to aim for. So for our example 100g system, a return pump that can bring us anywhere from 300gph to 500gph will be ideal.
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The next thing we need to discuss is head pressure. Pumps have varying amounts of torque so some will be better suited for jobs which have longer plumbing than others.
Let's assume our example 100g system has six feet of verticle plumbing from the sump to the outlet(s) in the display. If we're going for a pump with 500gph, we will need to take that head pressure into account. An important thing to note here is that pump ratings always assume zero head pressure so if we buy a pump that has a "500 GPH" sticker on the box, we will not get anywhere near 500gph in our tank. Fortunately, most pump manufacturers provide nice charts such as the one below that will graphically show us how pipe lengths will affect the flow rate.
http://www.saltysupply.com/v/vspfiles/assets/images/waterblaster2000_flowchart.jpg
As you can see, buying this pump (Water Blaster HY-2000) based purely on the "550 GPH" sticker on the box would have ended badly for us because it can not handle the six feet of plumbing we have. We need to either get it's bigger brother (HY-3000/4000) or look for another brand that's a bit torquier.
One last thing to know is that a few pump manufacturers like Danner (Mag Drive series) calculate head pressure values with specific pipe diameters. I believe Danner uses 1.5 inch plumbing in their tests so smaller pipes are likely to further increase head pressure and lower overall waterflow.
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There are two types of return pumps: Internal and External. Before you choose a brand, you need to find out which type of pump will work best for you.
Internal pumps are the most popular ones. They can be fully submerged in the water.
Advantages are:
- Compact - excellent if you're limited in space.
- Quiet operation.
- Affordable.
Disadvantages are:
- Not good for high-head pressure applications.
- Heats up water due to submersion.
- Potential of electric hazard.
External pumps sit just outside the water column and pull in water through a pipe.
Advantages are:
- Does not heat up the tank water.
- Powerful. Excellent for high head pressure (10-15+ feet).
- Safe. No electric parts in water.
Disadvantages are:
- Requires space.
- Can be noisy.
- Can be pricey.
There are some internal pumps that can be ran externally also.
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There are so many different brands and styles of pumps to choose from, it will be overwhelming for some. Fortunately, since pumps are pretty varied, there are many ways to narrow it down based on what's important to you:
- Some have special features (Waveline DC, Water Blaster)
- Some are very affordable (Rio, Maxi-Jet)
- Some are very powerful (Mag Drive, ReeFlo)
- Some are highly trusted and durable (Iwaki, Eheim)
- Some are extremely quiet (Laguna)
- Some are energy efficient (Sicce, Tunze)
... and so on. Every advantage comes with a disadvantage. Do a bit of digging on manufacturer/retailer websites, read some reviews or search these forums. There's a ton of info out there.
Good luck. :rollface:
The first thing we need to look at are turnover rates. A turnover rate is your total water volume multiplied by X. A 100g system with a 3x turnover rate has 300gph of waterflow. With FOWLR systems, 5-10x will be enough, but sometimes you might want more so particles don't settle as easily. For reef tanks, you will need up to 30x and even more for SPS systems.
Fortunately we have powerheads and closed loop systems that handle most of the frontline work in terms of waterflow. This will make the return pumps job much easier. It still needs to be sized accordingly though!
The general recommendation for return pumps is one with a 3-5x turnover rate. You don't have to match this exactly but it gives you a good idea of what to aim for. So for our example 100g system, a return pump that can bring us anywhere from 300gph to 500gph will be ideal.
-----------------------------------------------------------------------
The next thing we need to discuss is head pressure. Pumps have varying amounts of torque so some will be better suited for jobs which have longer plumbing than others.
Let's assume our example 100g system has six feet of verticle plumbing from the sump to the outlet(s) in the display. If we're going for a pump with 500gph, we will need to take that head pressure into account. An important thing to note here is that pump ratings always assume zero head pressure so if we buy a pump that has a "500 GPH" sticker on the box, we will not get anywhere near 500gph in our tank. Fortunately, most pump manufacturers provide nice charts such as the one below that will graphically show us how pipe lengths will affect the flow rate.
http://www.saltysupply.com/v/vspfiles/assets/images/waterblaster2000_flowchart.jpg
As you can see, buying this pump (Water Blaster HY-2000) based purely on the "550 GPH" sticker on the box would have ended badly for us because it can not handle the six feet of plumbing we have. We need to either get it's bigger brother (HY-3000/4000) or look for another brand that's a bit torquier.
One last thing to know is that a few pump manufacturers like Danner (Mag Drive series) calculate head pressure values with specific pipe diameters. I believe Danner uses 1.5 inch plumbing in their tests so smaller pipes are likely to further increase head pressure and lower overall waterflow.
-----------------------------------------------------------------------
There are two types of return pumps: Internal and External. Before you choose a brand, you need to find out which type of pump will work best for you.
Internal pumps are the most popular ones. They can be fully submerged in the water.
Advantages are:
- Compact - excellent if you're limited in space.
- Quiet operation.
- Affordable.
Disadvantages are:
- Not good for high-head pressure applications.
- Heats up water due to submersion.
- Potential of electric hazard.
External pumps sit just outside the water column and pull in water through a pipe.
Advantages are:
- Does not heat up the tank water.
- Powerful. Excellent for high head pressure (10-15+ feet).
- Safe. No electric parts in water.
Disadvantages are:
- Requires space.
- Can be noisy.
- Can be pricey.
There are some internal pumps that can be ran externally also.
-----------------------------------------------------------------------
There are so many different brands and styles of pumps to choose from, it will be overwhelming for some. Fortunately, since pumps are pretty varied, there are many ways to narrow it down based on what's important to you:
- Some have special features (Waveline DC, Water Blaster)
- Some are very affordable (Rio, Maxi-Jet)
- Some are very powerful (Mag Drive, ReeFlo)
- Some are highly trusted and durable (Iwaki, Eheim)
- Some are extremely quiet (Laguna)
- Some are energy efficient (Sicce, Tunze)
... and so on. Every advantage comes with a disadvantage. Do a bit of digging on manufacturer/retailer websites, read some reviews or search these forums. There's a ton of info out there.
Good luck. :rollface: