Canister filter head height

the big kahuna

Dovii
Original poster
MFK Member
Oct 13, 2007
720
458
102
new york city
When referring to a canister filters head height for example an FX6 is 10.8 feet, does that mean vertical and horizontal? I'm questioning this because I set up a 54 gallon corner tank that has a few African Cichlids in it. The tank is set up behind a large piece of furniture. I'd like to upgrade and put a fx5/6 on it and have the hoses run behind the furniture from the tank to the filter that will be on the floor about 7 feet away hidden. Then I can have the filter sitting with easy access to it so I don't have to move the furniture to service the filter. Will this pose a problem with efficiency or overall performance? I realize an fx5/6 is overkill for that tank but if there's a decrease in flow, it just may work out. Also if it does work what would be the maximum distance to run the hoses from tank to filter? Any thoughts or suggestions would be great.
 

duanes

MFK Moderators
Staff member
Moderator
MFK Member
Jun 7, 2007
15,070
12,391
2,910
Isla Taboga Panama via Milwaukee
Head pressure is is how much vertical height the pump has to overcome to get water up.
The higher water has to be pumped, the harder the pump works and effects efficiency, and its gph.
Although vertical length can also effect efficiency.... its not to the degree that height does, but every little bends in plumbing effect efficiency to some degree. The numbers are all dependent on your tanks plumbing runs.
There are calculation tables available that can be used that you can punch your number in, to determine.
Do a search.
Back in the old days I had a book called Aquarium Engineering (or something on that order) that I used with a Texas Instruments calculator, these days with internet, it should be quite easy to determine by just plugging in the numbers.
 

Backfromthedead

Redtail Catfish
MFK Member
Jul 12, 2017
2,603
2,596
154
Fredericksburg va
While a canister on a closed loop doesn't exhibit head loss, friction loss does increase with the length an complexity of the loop. I found that my cans worked best when the input and output hoses were about th he same length and at the same height in the tank.

In short i think it would work ok, but probably not as well as more simple plumbing.
 
  • Like
Reactions: Oughtsix

Oughtsix

Dovii
MFK Member
Apr 9, 2011
1,341
335
107
Redmond, OR
Backfromthedead is correct. Head height is how much gravity the pump has to over come. In a closed loop system like a canister filter the inlet height and return height is the same so the head height is zero. The only the thing the canister pump has to overcome is the resistance of the tubing which increases with tubing length.
 

the big kahuna

Dovii
Original poster
MFK Member
Oct 13, 2007
720
458
102
new york city
Got it......thanks for the replies.
 

DN328

Aimara
MFK Member
Aug 14, 2014
2,213
892
135
Fish Tank
Backfromthedead is correct. Head height is how much gravity the pump has to over come. In a closed loop system like a canister filter the inlet height and return height is the same so the head height is zero. The only the thing the canister pump has to overcome is the resistance of the tubing which increases with tubing length.
I don't use canisters did not realize that equal height inlet/outlet basically does not impact head height?

On a related note, I saw a Marine Depot video where they did provide general numbers for vertical, horizontal and elbow PVC plumbing. Does not apply here but since we were on topic. I have no idea how MD came up with the figures.
 

Oughtsix

Dovii
MFK Member
Apr 9, 2011
1,341
335
107
Redmond, OR
I don't use canisters did not realize that equal height inlet/outlet basically does not impact head height?

On a related note, I saw a Marine Depot video where they did provide general numbers for vertical, horizontal and elbow PVC plumbing. Does not apply here but since we were on topic. I have no idea how MD came up with the figures.
Correct. Head height is the net height the pump has to raise the water. If the water starts at the same height is ends up at the head height is 0.

If you use a spray bar on your canister filter that sits 1 inch above the water level of the tank the head height of the system is 1 inch.
 
  • Like
Reactions: Backfromthedead

Backfromthedead

Redtail Catfish
MFK Member
Jul 12, 2017
2,603
2,596
154
Fredericksburg va
Correct. Head height is the net height the pump has to raise the water. If the water starts at the same height is ends up at the head height is 0.

If you use a spray bar on your canister filter that sits 1 inch above the water level of the tank the head height of the system is 1 inch.
That makes sense. For some reason i thought if the output was not submerged then it wasnt considered a closed loop.

But are you saying the head height would only change if it was above the waterline? What if it was still submerged, but higher up in the tank than the intake? Would that add head height as well?
 

Oughtsix

Dovii
MFK Member
Apr 9, 2011
1,341
335
107
Redmond, OR
That makes sense. For some reason i thought if the output was not submerged then it wasnt considered a closed loop.

But are you saying the head height would only change if it was above the waterline? What if it was still submerged, but higher up in the tank than the intake? Would that add head height as well?
When the intake is submerged in the tank the head height is calculated at the water line in the tank. When the return line is submerged the head height is calculated at the water line of the tank.

If the intake line is submerged and the return line from the canister it looped over a hook on the ceiling 4 feet above the tank but the outlet of the return line is in the tank the head height is 0.

If the intake line is submerged and the return line from the canister it looped over a hook on the ceiling 4 feet above the tank but the outlet of the return line goes to a spray bar 1 inch above the tank water level the head height is 1 inch.

If you have a sump on the floor 4 feet below the tank and the return line is looped over the top of the tank at 4 feet then goes to the very bottom of the 2 foot tall tank the head height is the difference between the water level in the pump compartment of the sump and the water level in the tank.

So 6" water level in the sump, Tank water line 2" below the top of the tank:

Head = 48" (top of tank) - 2" (water level to top of tank) - 6" (water level in the sump) = 40" total head.

I.e. In an open system like a sump the sump pump has to work a lot harder and uses considerably more energy than the pump in a closed loop canister. This is why pumps in canister filters are usually very wimpy when compared to sump pumps.
 
Last edited:

Oughtsix

Dovii
MFK Member
Apr 9, 2011
1,341
335
107
Redmond, OR
That makes sense. For some reason i thought if the output was not submerged then it wasnt considered a closed loop.
You are correct, if the return line from a canister is not submerged it is technically not a closed loop system. The head height is always calculated as the difference of water outlet level and the water level at the inlet (regardless of how deep under the water level the inlet tubing is placed).
 
  • Like
Reactions: Backfromthedead
zoomed.com
hikariusa.com
aqaimports.com
Store