Fluvals Flow Rates Anyone Managed To Get Them

[mystic.bertie]

years ago i tried this with a fluval external number 4 (the big one) i measure the flow rate the tank was getting and it was nowhere near what the fulval spec was, after much experimenting and checking flow rates i found that the thinner hose on the supply side was not even supplying enough water anywhere near what the filter was meant to deliver, so to cut a long story short i used the 22mm white plastic push fit plumbing elbows and the heavy fluval tubiong on both supply and output and i managed to get something very close to the specified flow rate, this was using 2 sponges and bio filter media.

i recently bought a full set up with a fluval 304 and 205 external filters, so i measured the output of the 304 and im getting 600lph with the standard tubing and fittings, i checked the water that was actually getting to the filter by measuring the amount by siphoning it and it only recieves 800lph approx, so there is no chance of the filter putting out 1000lph it specifies when the hosing they supply wont even deliver that to the pump, so has anyone recently done any modifications to their modern fluvals to improve the flow rates. As i have many malawis im looking for high flow rates so trying to maximise these filters.

the fluval fittings look decent and clend in with the tank well so i dont want something that will stand out as its a nice show tank in my living room.

 

[Schmill]

From what I have read this is a common 'trick' by all pump / filter manufacturers whether thats for ponds or aquariums.
The Fluval 304 spec says:

FLUVAL 304
Aquarium Capacity: 300 l/70 U.S. Gal.
Pump Output: 1000 l/h-260 U.S. g/h
Mechanical Area: 56,000 mm2
Biological Volume: 3,1
Filtration Volume: 6,6
Filter Circulation* 710 l/h-185 U.S. g/h
Water Column Height (max.) 1,60 m
*NOTE: Flow rates were measured with Intake and Output hoses that were the same length.

Note that in the Fluval spec they give a 'Pump Output' of 1000Lph. Similarly with my Aqua One they quote a 'Maximum Flow rate'.

On the Aqua One the 'maximum flow rate' is later specified as being the flow rate with no media in the filter, and 0m head lift (they get my respect for at least qualifying this which most manufacturers don't!)
As Fluval have spec-ed it as "Pump Output" I would guess that it's something similar, the maximum flow that the PUMP (note not filter!) can provide.

Again with the Aqua One, they also nicely provide a figure they call "Operational Flow Rate", which for my filter is given as 750Lph. This is specified as being a filter WITH media loaded, and a head of 1.6m lift (ie. a more realistic environment).

Looking at the Fluval spec name & numbers I would guess that their "Filter Circulation" figure is the equivalent, so I'm thinking you should be aiming at 710Lph with media and a 1.6m Lift.

Based on this the figures you are actually measuring seem a lot more reasonable

 

[rabbut]

I modified my Fluvals by binning them and replacing with a decent brand I hate the Fluval exturnals with avengance, they create excess noise, clogg easily, are hard to maintain and prime, and get noiser and loose flow as they get old, along with releasing electric shocks to their owners IME. Oh, and to top it off, they have a habit of leaking.... No chance you can take them back before you have any of these problems?

No, you will never get near the manufactirers specs, even with modifications. The hosing adds resistance, as does the filter media. If you increase the wideth of the hose, you loose some resistance, but not all. To see the kind of resistance involved in hoses, blow through a 1m length of air line, then try the same on a 100m roll. Things are 10x as bad for a fluid as they are for gasses, so that hose realy reduces the flow...

All the best
Rabbut

 

[waterdrop]

All of which is bound to make us all wonder whether the recommendations (very general) on TFF of people feeling 5x turnover or more if you feel the need for more, are most likely based on members looking as manufacturers -numbers- as opposed to actual water and stopwatch tests in their aquarium. I'm inclined to think lots of peoples recommendations are probably based on manufacturers numbers, wouldn't people agree with that??

~~waterdrop~~

 

[Miss Wiggle]

yes my recommendations are based on manufacturers numbers rather than actual speces as it's so hard to predict what they would actually be and it's not something you should expect the avergae aquarist to work out, they'll just read the box and take it as read that it does what it say's it should.

however 5x is pretty generous so if you actually end up with 4x then that should be ample really for most 'standard' tanks.

 

[mystic.bertie]

UPDATE
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 the filter too but its too awkward to test that filter flow rate due to its position.

 

[T1KARMANN]

I modified my Fluvals by binning them and replacing with a decent brand

All the best
Rabbut

i didnt know you had eheims

 

[rabbut]

I modified my Fluvals by binning them and replacing with a decent brand

All the best
Rabbut

i didnt know you had eheims

I don't think the old Ecco would fit into that category personally. IMO it was as bad as the Fluvals

 

[T1KARMANN]

I modified my Fluvals by binning them and replacing with a decent brand

All the best
Rabbut

i didnt know you had eheims

I don't think the old Ecco would fit into that category personally. IMO it was as bad as the Fluvals

the ecco is rubbish you spend budget money you get a budget filter

you spend good money you get a good filter

 

[rabbut]

I modified my Fluvals by binning them and replacing with a decent brand

All the best
Rabbut

i didnt know you had eheims

I don't think the old Ecco would fit into that category personally. IMO it was as bad as the Fluvals

the ecco is rubbish you spend budget money you get a budget filter

you spend good money you get a good filter

Or you can spend budget money on a Tetratec and still get a good filter I know which I prefur

EDIT to add, sorry OP, this is getting rather off topic. I'll stop now before your thread becomes another argument over wich is better, Eheim or Tetratec

 

[mystic.bertie]

EDIT to add, sorry OP, this is getting rather off topic. I'll stop now before your thread becomes another argument over wich is better, Eheim or Tetratec

FLUVAL for the win

 

[T1KARMANN]

I modified my Fluvals by binning them and replacing with a decent brand

All the best
Rabbut

i didnt know you had eheims

I don't think the old Ecco would fit into that category personally. IMO it was as bad as the Fluvals

the ecco is rubbish you spend budget money you get a budget filter

you spend good money you get a good filter

Or you can spend budget money on a Tetratec and still get a good filter I know which I prefur

EDIT to add, sorry OP, this is getting rather off topic. I'll stop now before your thread becomes another argument over wich is better, Eheim or Tetratec

true lets stop their

 

[adamgreen240]

Ive recently changed from fluval to eheim. I'm now an eheim guy!!

(As shown Below) lol

 

[jgray152]

along with releasing electric shocks to their owners IME.

What the hell are you talking about? I have never in the 10+ years of owning my 304 and listening to reviews, heard about owners getting shocked by their filter.

Where did this come from and how can you get shocked?

 

[rabbut]

Dodgy motor unit can seap voltage into the tank Happend to me when my old 404 was dieing Normaly they just leak having had the seals pack up, the voltage seapage is quite rare though, but painful if it happens to you

All the best
Rabbut