External Filter Questions

[plecostomus-mad]

im not sure if this is the correct place to post this but i have a few queries.

i have a fluval 304 external filter and im not sure im getting the most out of it. i have placed the inlet at the bottom of the left hand side of the tank and the outlet is near the middle with the spray bar ( no end cap ) pointing down towards the heater.i took the end cap off the spray bar as i feel this restricts the maximum flow?

where would the ideal position be for the inlet and outlet?

does water absorb oxygen from movement at the surface or do i really need the use of an air pump and air stones etc? i took the air stones out this morning because my talking cat is rebelling against them every time i re-position them after he dislodges them and then the tank looks crap!

mark

 

[JenCliBee]

im not sure if this is the correct place to post this but i have a few queries.

i have a fluval 304 external filter and im not sure im getting the most out of it. i have placed the inlet at the bottom of the left hand side of the tank and the outlet is near the middle with the spray bar ( no end cap ) pointing down towards the heater.i took the end cap off the spray bar as i feel this restricts the maximum flow?

where would the ideal position be for the inlet and outlet?

does water absorb oxygen from movement at the surface or do i really need the use of an air pump and air stones etc? i took the air stones out this morning because my talking cat is rebelling against them every time i re-position them after he dislodges them and then the tank looks crap!

mark

Inlet/ outlet usually will be placed opposite ends of the tank, this gives the water most flow round the tank before it is re filtered basically.

As far as im aware air-stones within a tank do nothing until the bubbles hit the surface, breaking it causing the oxygen to be filtered through the water, Agitating the surface with the spray bar will work just as well if not better.

 

[the biffster]

have you got your filter at the same
high as your tank or is it beneath
the height of your tank . i find that
if you place the the spray bar facing
towards the front of the tank just below
the water level just slightly pointing up over
so it agitates the surface which is what you
are looking for

 

[plecostomus-mad]

have you got your filter at the same
high as your tank or is it beneath
the height of your tank . i find that
if you place the the spray bar facing
towards the front of the tank just below
the water level just slightly pointing up over
so it agitates the surface which is what you
are looking for

the filter is underneath in the cabinet, should i move it so its level with the tank?

im not sure if this is the correct place to post this but i have a few queries.

i have a fluval 304 external filter and im not sure im getting the most out of it. i have placed the inlet at the bottom of the left hand side of the tank and the outlet is near the middle with the spray bar ( no end cap ) pointing down towards the heater.i took the end cap off the spray bar as i feel this restricts the maximum flow?

where would the ideal position be for the inlet and outlet?

does water absorb oxygen from movement at the surface or do i really need the use of an air pump and air stones etc? i took the air stones out this morning because my talking cat is rebelling against them every time i re-position them after he dislodges them and then the tank looks crap!

mark

Inlet/ outlet usually will be placed opposite ends of the tank, this gives the water most flow round the tank before it is re filtered basically.

As far as im aware air-stones within a tank do nothing until the bubbles hit the surface, breaking it causing the oxygen to be filtered through the water, Agitating the surface with the spray bar will work just as well if not better.

im abit unsure about using a spray bar, well one with the bung in the end, this must restrict the maximum flow?

 

[the biffster]

no that's OK just how far below because
there is only a certain height that they
will pump to but if you put them level
they also lose flow also check that
there is no kinks in any of the pipes and the taps are fully open
also pulling the plug out of the end of the spray bar
will mean you wont the the spray effect of the spray bar
as it passes the smaller holes and goes straight out the
end of it

 

[plecostomus-mad]

i would say the filter is about 80cm-ish below the tank.no kinks etc. i realize there will be no spray from the bar with the plug out. i just think its losing its potential with the plug in. the filter is rated at 1000lph but i dont think its turning over that much.it is a second hand external i had with a tank, but its in new condition and the impeller is mint.i was expecting it to pump water around like mad considering the size of it, it doesn't seem to have anymore flow than the fluval plus 4 internal i was using.
i have had to put my fluval plus 2 in the tank just to make movement on the surface and it looks terrible. i wanted an equipment free tank( heater being the exception ). i may buy a bigger external.

 

[the biffster]

i think you would be better putting the plug
back in as its the spray that agitates the water
were it give several points of contact with the water
instead of only one was there any filter floss or carbon
in the filter

 

[JenCliBee]

i would say the filter is about 80cm-ish below the tank.no kinks etc. i realize there will be no spray from the bar with the plug out. i just think its losing its potential with the plug in. the filter is rated at 1000lph but i don't think its turning over that much.it is a second hand external i had with a tank, but its in new condition and the impeller is mint.i was expecting it to pump water around like mad considering the size of it, it doesn't seem to have anymore flow than the fluval plus 4 internal i was using.
i have had to put my fluval plus 2 in the tank just to make movement on the surface and it looks terrible. i wanted an equipment free tank( heater being the exception ). i may buy a bigger external.

The filter is 1000lph without media, once media is in you will be lucky to get 600lph. Combine that with the fact that the filter is very old which again would probably lose you more flow.

I'm presuming this is on your 50g tank?, The filters are usually quite good, i had the 305 running on my 47g and even though it kept the water clear the actual flow was far from sufficient, i added a powerhead to get round this. Obviously from your post's you want a virtually empty tank ..ie equipment?, the only way you will make any difference with the filter is upgrade it, maybe the 405 which i know to be very good and would suffice the 50g, there is also the TT ex12 again very good and equivalent eheim models with overall, views are rated the best filters around.

Not to get into some sort of debate on filters and which are best but ive never had a single problem with fluvals so my opinion would be upgrade to the 405 and see if that makes any difference to you.

 

[OldMan47]

If you feel you must have high flow for some reason, a larger filter pump is indeed the solution. If you are just being overly influenced by the flow multiple people, relax. A filter at far less than 1x is more than adequate for fish. The critical parameter for a biological filter is its capacity to hold biological media. The only flow it needs for that to function is enough to bring some water past the media before the ammonia in the tank can build up.
Plant people are very biased toward high filter flow rates because they believe that they can prevent algae growth in a tank by having good water mixing and can even prevent any localized low flow areas by using high pumping rates.It all makes sense in terms of higher flow preventing localized stagnation but I am not sure it is really needed for planted tanks.
Other functions for a filter are chemical and mechanical filtration. Mechanical filtration, making the water seem clear, can indeed be helped by higher and higher flows up to the point that the flow itself causes material in the tank's substrate to be stirred up into the water column. Chemical filtration works best with nice long contact times between the chemical contaminant and the chemical media. Again we are going to say that low flows are not a problem for chemical filtration.
OK, where are we left? If you want a healthy fish tank, you really only need to worry about having adequate volume in the media containers to hold a good selection of media. If you want crystal clear water, higher flows up to a point may very well help but a great looking tank can be achieved by merely using a gravel vac to remove all debris from the surface of the substrate. If you are a plant person, I cannot refute the reasoning they use but suspect it is no more supported by actual needs than the "need" of high flows for fish.

 

[plecostomus-mad]

thanks oldman47, thats cleared up alot of extra questions i may of had
i guess i was just a little worried my filter wasent pumping the water around my tank enough.

the pic below is a diagram o how i have it set up. the red rectangle is my heater, i thought ( might be wrong ) that its best to have the out flow going past the heater for better heat distribution? if you think im better off setting it up another way,please do tell me the star is where i have next to no water movement, i know this as one of the plats do not movement all.

 

[OldMan47]

It is indeed a good idea to have decent flow rates near the heater so that the water does not end up having warmer and cooler locations in the tank. In most of my larger tanks, I have started using an inlet at the bottom back of the tank in a corner and am returning to a spray bar at the opposite end of the tank. I do not angle the flow the way you have but keep my spray bar rather level about 2 or 3 inches below the water surface with flow going out parallel to the water surface. That gives me great flow patterns in the water anywhere near the spray bar and by returning high and having an intake low, I also get some vertical mixing. There may be some dead spots in my tanks because I don't go all around trying to judge the flows in specific locations but the filters function to maintain good water quality and my plants grow like the weeds they are.

 

[raptorrex]

thanks oldman47, thats cleared up alot of extra questions i may of had
i guess i was just a little worried my filter wasent pumping the water around my tank enough.

the pic below is a diagram o how i have it set up. the red rectangle is my heater, i thought ( might be wrong ) that its best to have the out flow going past the heater for better heat distribution? if you think im better off setting it up another way,please do tell me the star is where i have next to no water movement, i know this as one of the plats do not movement all.

there is a, valid, view that runs contra to oldmans comments. a cannister at 1 0r 2x flow is not efficient. either biologically or mechanically.
5x real flow is sought, as a minimum, by many. though poo pooed by a mod hear, its a valid and effective solution. I, and many others, would say your tank is under filtered (even with a empty version of your filter).

 

[N0body Of The Goat]

At the moment we seem to have similar setups, plecostomus-mad, but I have chosen the positioning due to electric point limitations (and I've sometimes wondered if there was a better way of positioing my filters...

• The Juwel 1000 pump outlet flows out horizontally from the heater/fiter chamber of my Rio240, flowing from back-right to back-left along the wall.
• The inlet for my Eheim 2078 is positioning in the front-left corner of the Rio.
• The outlet for the Eheim enters the tank via the back-left cavity and the spraybar is then angled at ~45 degrees, towards the wall behind the tank. Usually I have the spraybar ~2cm above the waterline, angled up slightly, so the water arcs into the tank and itslow then combines with the Juwel 1000 flow. Out of curiousity, today I've submersed the spraybar just below the waterline, fractionally pointing the holes upwards. Its certainly quieter, I don't feel as I'm sitting next to the Congo Rapids anymore!
  
• The deadspot in my tank is the front-right, where my new male African Butterfly Fish chills out most of the day (although sometimes he enjoys a bit of current surfing in the front-left corner). I currently have my spare, easily transportable, Juwel Compact/280 just away from the front-left corner. Its trickle is a mini wterfall feature facing the back-right corner.

A lot of flow for most fish, but I'm considering the addition of a Wavemaker 12000 (cheap and cheerful and very tempting to try) or a Hydor Magnum 8 (same 12500 litres per hour rating, but through just a single powerhead rather than two)! But then my Rio240 is occupied by riverine fish, that need the current and consequent high oxygen saturation (from ideally keeping the temp below 24C)

 

[Dave Spencer]

Plant people are very biased toward high filter flow rates because they believe that they can prevent algae growth in a tank by having good water mixing and can even prevent any localized low flow areas by using high pumping rates.It all makes sense in terms of higher flow preventing localized stagnation but I am not sure it is really needed for planted tanks.

It makes a lot of sense in higher energy planted tanks. In slower growth tanks, flow, like everything else (carbon, ferts etc), become far less important.

Leaving the end cap will result in the water at the outlet taking the path of least resistance, and just slowly spilling out at the end of the spray bar, giving very slow, localised flow. Your best bet would be to put the cap back on, and force the water out of the holes in the spray bar, giving smaller, higher energy jets more evenly distributed.

Dave.

 

[RadaR]

Yes, high energy planted tanks require good flow and circulation in order to deliver resources (nutrients and CO2) to the plants at efficient rates. Lack of this would most likely result in "hungry" plants, which just opens the door for algae.
As Dave as mentioned, with lower energy planted tanks, the demand for this flow decreases.