I'm thinking of combining my 2 canister outputs to one.

[zachjohnson65]

Does anyone know of any problems with combining my 2 canister outputs into one with a barbed Y fitting? I figure it would allow for a single spray instead of two. I was thinking that i could put my in line heater after the Y to insure that i never lose heat even if one of the filter goes. The filters are a Via Aqua (300 gph) and a eheim 2213 both with 1/2" tubing. Thanks Zach

[Blueiz]

The only problem I see is that the size of the spray bar will not accomadate the outflow therefore putting a restriction of your filtration. Back pressure from this could overwork your pump as well as cause hoses to "blow" apart.

[zachjohnson65]

i was thinking of using 1/2" PVC for a DYI spray bar. Would that still be too restrictive?

[Rbishop]

find the cross sectional area of the 1/2" outlet of one filter...double it.....then the cross sectional area of the spray bar should equal that.

You will have issues though if your two filters do not have equal discharge pressure...

[zachjohnson65]

as far as pressure goes. I know my via aqua says 330 ghp but by feeling the water output i would say it is closer to my eheim 2213.
I knew should have ordered the water flow gauge from Drs. fosters when i ordered recently.

[Squawkbert]

I think this will end in tears. Don't do it.

[6.5x55]

I was thinking of a similar thing for when my 100 arrives. Could I use a single out-take and return fitting and use Y tubing adaptors to feed two identicle canister filters?

[The Zigman]

I would definately check valve both outlets so if one pump fails, you dont backwash through the filter media and pollute your tank...

[Sploke]

I'd keep them separate.....more dispersed flow >> more concentrated flow, it will help circulate the water better and keep the tank cleaner.

[6.5x55]

Cheers guys, didn't think of that. If one stopped, gunk from the other one could get sucked up into the return. Probably just go for a 2028 then :).

[jmhart]

I know many people that combine their filters. While many possible hazards exisit, most are not probable. My wife(Chemical Engineer) helped me brainstorm this idea a while back. To note, she didn't actually do any calculations or anything, but she advised me on theory.

If your head pressure is less than the output pressure of the weaker filter, you won't have any problems with backflow unless that weaker filter fails. For your average head of 6 ft, this isn't a problem for the pumps in the fitlers we all use. The filter shutting down is on you, though, cause sometimes filters just break, and if this occurs, back flow will happen.

Like I said, many people plumb filters together. For a few ideas check out these links:

http://www.bharada.com/aquaria_120.html

http://www.plantedtank.net/forums/equipment/34969-my-automatic-water-changer-setup.html

http://wetplantlogic.com/wordpress/wp-content/uploads/2008/06/tank-plumbing-v10.jpg

It certainly is a little safer if all the filters are the same, but you can kind of average it out. For example, I'm planning to pipe mine in parrallel eventually, where I have three filters on a 180g tank: 2 Eheim 2128s and a Mag 350. I'm planning to plumb a hydor inline inline with one of the 2128s and a UV sterilizer inline with the other 2128 to drop the pressure before the lines combine with the 350. Something like the attached image

[Rbishop]

Well..while it may not completely reverse flow in the less capable pump...it will restrict flow thru it. Some folks may need to review fluid flow equations.

Slowing the flow in another filter is the same as having a smaller filter...of no use for the bucks you spent...

Parallel operation only works with certain types of pumps..not all.

[jmhart]

Well..while it may not completely reverse flow in the less capable pump...it will restrict flow thru it. Some folks may need to review fluid flow equations.

Slowing the flow in another filter is the same as having a smaller filter...of no use for the bucks you spent...

Parallel operation only works with certain types of pumps..not all.


All are true and valid points. It certainly will slow down flow through the less powerful pump, but again, no reverse flow unless head pressure is too great.

Additionally, adding devices for the sole purpose of slowing flow does seem counterintuitive, unless you are planning to add those devices anyway. It was really more of a note to point out to add those to the more powerful pumps.

And finally, for the pumps used in the most popular aquarium filters, than can be plumbed in parallel, in fact plumbing in parallel is a better option than even considering in series.

[Rbishop]

I would disagree...but thats IMO...no consideration at all for in series...they are designed for independent ops..