View Full Version : Fluval Cannister Question

01/15/2007, 09:01 AM
Okay folks...I have a Fluval 404, the newer version, and I want to use it as a cleaner for my 70 gallon Roughneck tub. The tub WILL BE, isn't yet but will be, my new fuge for me 135 Reef.

The 404 is going to have charcoal and some sponge in it and one small layer of biostars in a basket. The charcoal is the correct kind, though the brand name escapes me at present, that is not activated with phosphorus so I am safe there!

Here's the situation...My roughneck is in my garage and sitting on the floor. I know that the 404 is a gravity feed type of cannister so my thought is to put it on some 4x4's to raise it up. Do you think I have to raise this tub up completely ABOVE the cannister lid to make the flow work propperly OR just slightly higher than ground level so that gravity is influenced enough to get it moving???

Thanks in advance for all of your suggestions !

01/15/2007, 10:29 AM

01/15/2007, 02:19 PM

01/15/2007, 02:27 PM
I would think that the water level in your tub would need to be higher then the top of the intake...also....dont they have that strange vacuum thing going on know...

01/15/2007, 03:07 PM
....strange vauum thing...? What strange vacuum thing...?

01/15/2007, 03:11 PM
I think the new fluvals have the manual pump thing to start water flow.....(I think due to that both intake and output need to be below water level)...and becuase of that, it really no longer relies on gravity feed anymore...(I could be wrong though)....just remember reading about that somewhere.....

01/15/2007, 03:15 PM
just read the manual....you need to be below water level (no less then 7").....
it is still gravity fed.....

01/15/2007, 03:28 PM
Okay...so if the top of the cannister is greater than 7 inches below the top of the water level...then it should flow just fine...yes?

01/15/2007, 03:34 PM
The fluval will work at ground level though Im not sure what the flow rate would change to, and may well have impact on pump life. The biggest hurdle would be to get it going. I have used a a small power head on the intake to start it. Theoretically maybe you could add a bulkhead or two to the tub that are constanly submersed rather than an over the top or hob type of plumbing arrangment. fyg i have used both a fluval and a filstar (in the past)as a low flow supply for my uv sterilizer at ground level(and even over the sump) fed from my sump. definatley would not recommend that as neither reliably restarted after a power interuption. as a mechanical filter for a sump i probablyt wouldnt worry abt it, to sustain bacteria though,probably not a good idea either.

01/15/2007, 03:38 PM
I'm sure what sandman said is accurate also, but I would think it wouldnt be very good for the "motor" either....one power loss and the impeller would be running dry.......

01/15/2007, 03:45 PM
okay...I did some measuring and at ground level the top of the cannister sits at 7.5 inches below my projected water level.

To aid in the flow; I will put the roughneck on a 4x4 frame brace which will elevate the water level to 11 inches above the top of the cannister !

Your thoughts please..!

01/15/2007, 04:02 PM
start filtering!

01/15/2007, 04:17 PM

01/15/2007, 05:26 PM
I doubt you will need to raise the container, should be fine at 7.5" below water level.