More Air into canister filter?

[Bob cratchet]

Thanks everyone that took the time to reply to my post a number of interesting points have been made. I'm going to
1)get a dissolved oxygen meter to test IP /OP to the filter for differences
2) tearup a spare canister and put a viewing window into to observe water /air flow mix and see if mechanically it's possible.
3) if 2 can be made to work run some tests to see if after all this it makes any decernable difference.
4) compare 1 against tests in 3
5) at some point watch my fish

It would be nice to just add a pipe to the input and increase efficiency whether it's worth the effort still remains to be seen....

 

[neutrino]

Might be an interesting way to pass the time for someone who likes to tinker with things. Personally, while I like the science, aside from having experimented with food, media, and filter types, I like things simple and I'm happy to leave the engineering to someone else.

 

[andyroo]

A can is designed for a steady pressure of water only - bubbles will get in the way, causing pressure variations within the lines & the canister & cavitation at the propeller/impeller causing noise and inefficiency & wear. Bubbles on the downstream line or in a secondary canister downstream might be interesting, but you'd want to be careful that bubbles don't pool or, again, you might get pressure and/or syphon issues.

A DIY thought from years ago was to plum the up-line (from can to tank) as a >4" pipe with a side vent to the tank but an open top to above the tank-water level. Me, I was going to use a clear pipe and add filamentous plants, but to put an air-stone at the bottom and rolling media might be pretty cool. Media would be buoyed by both air & water flow, so would need to be quite strongly-sinking.

 

[TwoTankAmin]

Very early on in my fish keeping history I used to chat with a gent who made his living working with huge pumps. The kinds in dams, desalinization etc. He taught me never to impede the flow on the intake side. The other thing one needs to avoid is excess gases in the canister. A noted above, it normally will result in cavitation.

When I got involved with live plants in year two in the hobby I decided to try a high tech planted tank which used pressurized CO2. I had space limitations and could not use a diffuser either inside or outside of the tank. My solution was to push the CO2 directly into the intake of the canister. I ran a faitly lean mix on this 50 gal tank, 1 bubble per second or a tad less. In order to have any chance at the canister not self destructing from years of CO2 being bubblede through the filter I determined the only canister up to the job was one made by Eheim (a Pro II 2026).

I ran it this way for about a decade when I decided to give up the tank. I still have that canister running today. No co2 going through it, but it still runs great and is as quiet as the day I first hooked it up.

I prefer to rely on surface agitation to oxygenate tank water.

 

[Zanzag]

I use a setup like this on my AC filters. It could be changed up to run on a canister.
This just forces the filter to pull from near the surface, using more oxygen rich water. It could accomplish your goal without the risk on your filter.