Fluvals Flow Rates Anyone Managed To Get Them

[Tommydeal]

So is the theory behind ribbed fluval tubing versus eheim tubing that the ribbing creates enough friction to reduce the flow? I've got a bunch of fluvals and would also be interested in maximizing their performance. About the spray bar though, a shorter spraybar would shoot the water out with more force but would not output more water. More holes = less restrictive and weaker current. Less holes = more restrictive and stronger current. I agree with the powerhead idea, that's a smart way to get more current. Even the best fluval mod won't increase the current as much as a powerhead would.

 

[mystic.bertie]

i have modifed the output and return tubing on my fluval 304, when i checked it as standard i got about 600lph, quoted is 1000lph, after my modifications i am now getting 820lph so all in all a worth while excercise although still not near what fluval specify, also when i did the test i had my bucket at the same height as the top edge of the tank, i marked 10l in my bucket and filled to that mark and timed how long it took to fill 10l into the bucket. I now have 22mm pushfit rigid plastic tubing and using the pushfit connections for both in and outputs.

i used the bigger fluval tubing from the 304 to use on the 205 and i would assume it will have improved the flow rate of thie filter too but its too awkward to test that filter flow rate due to its position.

 

[puntoturbo]

i have modifed the output and return tubing on my fluval 304, when i checked it as standard i got about 600lph, quoted is 1000lph, after my modifications i am now getting 820lph so all in all a worth while excercise although still not near what fluval specify, also when i did the test i had my bucket at the same height as the top edge of the tank, i marked 10l in my bucket and filled to that mark and timed how long it took to fill 10l into the bucket. I now have 22mm pushfit rigid plastic tubing and using the pushfit connections for both in and outputs.

i used the bigger fluval tubing from the 304 to use on the 205 and i would assume it will have improved the flow rate of thie filter too but its too awkward to test that filter flow rate due to its position.

Good job mate! 820lph is not bad for a 304 compared to what is was previously 600lph. Did you shorten the tubing as much as possible????

 

[mystic.bertie]

Good job mate! 820lph is not bad for a 304 compared to what is was previously 600lph. Did you shorten the tubing as much as possible????

thanks . yeah they were as short as possible anyway and filters directly below the tubs in the cabinet, so they are not any longer than they need to be.

 

[Tommydeal]

Do you have any pictures of the connections you made on the fluval? Does the rigid tubing you used fit into the same connector as the ribbed fluval tubing?

 

[mystic.bertie]

Do you have any pictures of the connections you made on the fluval? Does the rigid tubing you used fit into the same connector as the ribbed fluval tubing?

yeah amazingly the tube was a nice tight fit on the nozzles and the nuts could still be turned to grip the pipe just like the original ones. Ill try and get some pics up later.

 

[Jgray152]

I just bought the eheim tubing from my local aquatic fish store! but im sure you can find a place online that sells eheim tubing.On my 405 i replaced the output nozzle with a eheim diffuser BUT if you want more FLOW i would go with the origonal nozzle that comes with the 404/405. I dont rate spray bars UNLESS you cut them shorter so theres not as many holes meaning more stronger output/flow! i only do this with spray bars on my Eheim canisters.If your looking for current,throw one or two LARGE power heads in your tank alongside your fluval canisters!

Doesn't a shorter spray bar with fewer holes = more of a restriction and LESS flow?

Trust me it doesnt. I have been doing this for YEARS!

THere is some confusion on both sides. Reducing the amount of holes in a spray bar will increase the pressure within the pumping system reducing the total volume of flow and velocity of flow but will increase the velocity of flow through the spray bar HOLES.

Same thing happends when you reduce the size of the output nozzel.

Using a smaller hose will increase velocity of flow which will increase the pressure within the hose and will have a stronger flow out through the output but the volume of flow will be reduced. With this said, this could be one of the reasons why Ehiem and other manufactures are using smaller diameter hoses on the filters. THey may be trying to get the velocity of flow up to create a current in the tank to either (A) help with circulation or (B) make you believe their filter has more flow when it does not.

Increasing the diameter of the hose could increase volume of flow but will reduce the velocity flow which means, yes you are moving more water through the filter but you are not going to create as much currect in the tank and you may then need a power head.

You also don't need to use "EHiem" hose. Go to Home depot and by some vynal tubing.

So is the theory behind ribbed fluval tubing versus eheim tubing that the ribbing creates enough friction to reduce the flow

That is correct. The ribbed hose will create lots of turbulance which will reduce the volume and velocity of flow. You need a higher pressure to move 400 GPH of turbulant flow than 400 gph of lower turbulant flow.

 

[CoryWM]

This thread is interesting to me. anyone have any articles related to hose length reducing flow etc?

 

[Jgray152]

do a search online. When you search, use the term "fluid" and not "water" when looking for articals on flow. So you can search for "hose length vs fluid flow" and you may get something.