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Discussion Starter · #1 · (Edited)
I have started a comparison sheet for canister filters since so much people ask questions pertaining to this. I have compiled information collected from various sources and still need more info to complete it. Any suggestions/information are welcome. This is a living document so I will update with additions/changes. Hope this helps! :biggrin:

Canister Filter Comparison Spreadsheet
 

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That is a lot of interesting information. I like it, mostly because I like stats. However, the one thing people will be most interested in, advertised flow rate vs. actual flow rate, is pretty impossible to put in a spreadsheet w/o a constant of "head".

For the most part, a canister filter is a bucket, which you can fill with media, into which water flows by gravity, out of with water is pushed back into the tank with a pump. How fast any pump moves water is greatly affected by how far uphill it must push the water. For example, my Rena XP2 is pushing water up about 2.5 feet along about 4 feet of tubing and I'm getting (through a very rough estimate of 1 Mississippi 2 Mississippi counting while holding a 5 gallon bucket at that height) 200 gph with a clean filter. Yet if that water had to go another foot higher, or along more tubing, the flow rate would be reduced.

Some pumps are much more affected by this "head pressure" than others. For example, both the Via Aqua 180 and Eheim 1046 advertise a 80gph flow. The Via Aqua advertises a 2' max head and the Eheim a 4' max head. The "max head" is how many feet up the water can be pushed before the pump simply fails to move any water. As these are all magnetic drive pumps, I'm guessing it has something to do with the strength of the magnets.

The media in place might have an impact as well, but I'm not so sure about this as the filter is lagely filled by gravity, not much by suction from the pump. If media or the intake was a limiting factor in flow rate, it could easily be improved with a wider intake tube...and as there aren't any filters with super fat intakes (when compared to the return) out there, I'm guessing this isn't that important...but someone with more knowledge of fluid dynamics than I could correct me.
 

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Discussion Starter · #4 ·

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That is a lot of interesting information. I like it, mostly because I like stats. However, the one thing people will be most interested in, advertised flow rate vs. actual flow rate, is pretty impossible to put in a spreadsheet w/o a constant of "head".

For the most part, a canister filter is a bucket, which you can fill with media, into which water flows by gravity, out of with water is pushed back into the tank with a pump. How fast any pump moves water is greatly affected by how far uphill it must push the water. For example, my Rena XP2 is pushing water up about 2.5 feet along about 4 feet of tubing and I'm getting (through a very rough estimate of 1 Mississippi 2 Mississippi counting while holding a 5 gallon bucket at that height) 200 gph with a clean filter. Yet if that water had to go another foot higher, or along more tubing, the flow rate would be reduced.

Some pumps are much more affected by this "head pressure" than others. For example, both the Via Aqua 180 and Eheim 1046 advertise a 80gph flow. The Via Aqua advertises a 2' max head and the Eheim a 4' max head. The "max head" is how many feet up the water can be pushed before the pump simply fails to move any water. As these are all magnetic drive pumps, I'm guessing it has something to do with the strength of the magnets.

The media in place might have an impact as well, but I'm not so sure about this as the filter is lagely filled by gravity, not much by suction from the pump. If media or the intake was a limiting factor in flow rate, it could easily be improved with a wider intake tube...and as there aren't any filters with super fat intakes (when compared to the return) out there, I'm guessing this isn't that important...but someone with more knowledge of fluid dynamics than I could correct me.
Lots of good guesses... but the head pressure is zero for canister filters. They are closed loops, so what applies to sumps does not apply to them. All the canister pump has to overcome is the friction introduced by tubing and media.

OP - nice work on the spreadsheet. Many of the flow rates depend a lot on your setup and measurements. I measured my XP3 having 250gal/hr with clean (sponge) media.
 

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Discussion Starter · #6 ·
Updated spreadsheet with some measured values found on forums and manufacturer site.
 

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also Canister flow rates are taken without media in the unit!
 

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Lots of good guesses... but the head pressure is zero for canister filters. They are closed loops, so what applies to sumps does not apply to them. All the canister pump has to overcome is the friction introduced by tubing and media.
Which is called head, and is significant. Also, the pressure in the canister is going to change with distance below the tank, and this will affect the efficiency of the pump.
 

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Lots of good guesses... but the head pressure is zero for canister filters. They are closed loops, so what applies to sumps does not apply to them. All the canister pump has to overcome is the friction introduced by tubing and media.

OP - nice work on the spreadsheet. Many of the flow rates depend a lot on your setup and measurements. I measured my XP3 having 250gal/hr with clean (sponge) media.
Oh...had not thought of that. That the pressure would be equalized from both ends. Thanks for correcting me. The DIY canister filter I'm working on is going to be way overpowered as the pump i got for it assumed it had 4.5 feet of head to deal with :)
 

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Discussion Starter · #11 ·
Edited spreadsheet, tried to upload a pdf version but file is too large to attach
 

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I asked the admin if the allowed pdf size can be a bit increased. Will let you know.

One thing I noticed, you had the HOT Magnum 250 on your list. It is sort of a cross-over between canister and closed-up HOB filter. I wonder if someone with a Kill-A-Watt or such device could check the wattage on that one. 11W seems really low for its water output. I guess the lack of hoses makes that one really efficient.
 

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I asked the admin if the allowed pdf size can be a bit increased. Will let you know.

One thing I noticed, you had the HOT Magnum 250 on your list. It is sort of a cross-over between canister and closed-up HOB filter. I wonder if someone with a Kill-A-Watt or such device could check the wattage on that one. 11W seems really low for its water output. I guess the lack of hoses makes that one really efficient.
Hoses wouldn't affect it. I just read here that canisters see 0 head.
:wink: :icon_wink
 

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Discussion Starter · #16 ·
Updates and added Eheim Ecco models
 

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Discussion Starter · #17 ·
Made minor updates and layout changes. Posted updated pdf, didn't post Excel file (redundant).
 

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It would be good to add watts per GPH to show efficiency. Ehiem has great efficiency which adds up on hydro costs over time. would be good to show cost to operate for 1 year (assume some average cents per KWH)
 

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Discussion Starter · #20 ·
Watts per GPH would be = watts/gph? And for operating cost for a year, would that be = watts*((365*24*$0.15)/1000)? My kWh rate is about $0.15 right now.
 
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