Go Back   Aquarium Advice - Aquarium Forum Community > General Aquarium Forums > DIY Projects
Click Here to Login

Join Aquarium Advice Today
Thread Tools Search this Thread Display Modes
Please support our sponsors and let them know you heard about them on AquariumAdvice.com
Old 11-26-2014, 01:37 PM   #1
Aquarium Advice Regular
Join Date: Aug 2014
Posts: 57
canister diy question

I have plenty of stuff laying around to try a diy canister filter. One question that i have seen several places is head pressure to pump up to tank. Water seeks its own level, so if it is a closed system, would the pump (power head) just be moving water as it is in an under gravel system? My Grandfather had a gravity filter on a 55 back in the eighties with two inputs and one output. Once he got the siphon going it would run on its own with no pumps. So a 1" overflow with 1/2" return should work. I am using dollar store plastic scrubbies for media. I plan to use a 170gph powerhead. First try will be on my ten gallon then this spring will be a pond or bigger tank.

PA Pat is offline   Reply With Quote
Old 11-26-2014, 03:52 PM   #2
Aquarium Advice Addict

POTM Champion
Join Date: Apr 2014
Location: Southern Cali
Posts: 1,734
How did it work without a pump?
Once the water level has reached equilibrium, any flow will stop.
The easiest way to make gravity work for you is to put the return pump/powerhead as close to the surface/end of the hose run as possible pulling water through the filter.
That way, as you pointed out, the water will seek it's own level and then the pump only has to move it a few inches and head pressure is no issue.
If you try to push the water out of the tank and through the filter, then you have to contend with head pressure and all that.

hope that made sense
PB_Smith is offline   Reply With Quote
Old 11-26-2014, 04:23 PM   #3
Aquarium Advice FINatic
Join Date: Jun 2014
Location: Cape Coral, Florida
Posts: 537
I'm not completely sure of your question, but pump sizing is related to static head pressure (water height, to over-simplify, in this case zero) as well as dynamic pressure from friction in the piping. There are formulae and tables for calculating equivalent head pressure based on pipe size, fittings, and (one of the most important) water flow velocity. Dynamic head pressure (or more properly "frictional head losses") vary as the square of the velocity, so larger pipe makes a huge difference.

Placement of the pump in a closed system makes no difference. But an overflow may not be a closed system in a pressure sense. Water falling freely into a sump for example "wastes" the energy as it falls. Pumping back up from a sump into the main tank then has the static head pressure of the difference in water levels in the main tank and sump, PLUS the dynamic head loss from friction due to length and size of pipes.

So your comment on overflow seems at odds with the comment on it being a closed system. Unless the overflow is kept completely full at all times, somehow.
Linwood is offline   Reply With Quote

canister, diy, question

Please support our sponsors and let them know you heard about them on AquariumAdvice.com

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Penn Plax Cascade Canister or Fluval 06 External Canister Filter blueramboy87 General Hardware/Equipment Discussion 1 01-28-2013 04:32 AM
DIY Canister Filter Question Kelso DIY Projects 0 08-29-2010 11:09 PM
DIY Background Tile Weight Question NOT A DIY PROJECT jThessin General Hardware/Equipment Discussion 4 11-01-2005 10:35 AM
Via Aqua Canister vs Fluval Canister Filter? TygGer General Hardware/Equipment Discussion 15 09-19-2004 02:09 AM
DIY Canister Filter Electrobes DIY Projects 19 09-21-2003 03:10 PM

» Photo Contest Winners

All times are GMT -4. The time now is 01:18 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.