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Sponge Filter


  1. [f][filtration] My 20 gal.
    by (Eric) (11 Feb 92)
  2. clogging sponge filters
    by (Jim Hurley) (9 Apr 92)
  3. New to list...lotsa Q's...
    by Ken Laidlaw <K.Laidlaw/> (Tue, 13 Jan 1998)

[f][filtration] My 20 gal.

by (Eric)
Date: 11 Feb 92

In article <> writes:
>I'm in the process of transfering my fish to a 20 gal. long.  Does anybody have
> any ideas on what size/type of filter to use.  Is a Whisper III to much? And l
>ast but not least, What is a powerhead and  what do you use it for?
>                                                      Thanks much,
>                                                         Tim

Question 1:
       As long as you do not overstock the tank, a sponge filter is adequate.
I have found in my 10 years of experience w/fresh water fish that power filters
seem to die to quickly.  Also, a Whisper III will really churn the water
which is not beneficial to slow water spiecies.  The sponge filter that
I am referring to is the home made type, the cheapest and best in my oppinion.
These are really great if you have a lot of tanks.  They were viable for me
because I was opperating a small fish room with approx.  30 tanks from 80 to
10 gallons.  They were on central air.  To build the sponge filters, you need
to get some 4" thick open celled foam.  The easiest place to find this is 
at a reappolsterers.  Ask if they have any scraps; sometimes you can get
them for free.  When you have the foam, cut it into 5" square peices either
by using a razor blade or by dipping it in water, freezing it and then use
an electric knife to cut it(do the last one only if you are making a lot.  
Lot of wives don't like this one either).  Then make a hole in it by 
sharpening the end of 1/2" rigid copper tubing and using it as a makeshift
drill.  Works great.  Then stick in some 3/4" pvc pipe, and elbow, and 1/8"
clear tubing and you have yourself a great sponge filter for a fraction
of commercial models.  The area of these sponges is quite larger too.

If this is too much for you, I would just recommend a commercial model.

Question 2:

       A powerhead is a submersable water pump intended for use with 
undergravel filters.  They attack to the uplift tube and pump water out
at an adjustable rate.  They make undergravel filters viable for larger tanks.
Some have what is called "venturi".  This is simply the way that a powerhead
draws in air to mix with the outgoing water stream.  

In my opinion, however, undergravel filters are not the most efficient 
ways to filter your water.  They really get messy after a while.  I stick 
more with sponge filters, and suggest that you do to.  Lately, I have
been using powerheads to power the wet/dry filter on my freshwater plant tank.


clogging sponge filters

by (Jim Hurley)
Date: 9 Apr 92
Newsgroup: alt.aquaria,rec.aquaria

In <> (Robert Frederick Enenkel) writes:

[about clogged sponge filters]

>Robert Enenkel

My wife and I have been using the Tetra PHAS sponges, which certainly
look the same, for about a year with no problems. One is used
constantly as the sole filter on a 27g tank of assorted Tetras
and angelfish. The other is a spare that I keep running in various places,
usually the sump of my 100g tank.

She cleans it like you do, squeezing into a bucket of water from the tank.
She usually cleans it once a week.
The spare hasn't been cleaned in months, but doesn't get much crud.

Maybe it's clogging with algae or other sorts of wildlife?

A while back, J. DeRosa posted about the his experiences with sponge filters.
Since it's a pretty good article, I pasted it below.


From rec.aquaria Fri Jan  3 13:20:00 1992
~From: ( rosa)
~Newsgroups: rec.aquaria,alt.aquaria
~Subject: Powerhead sponge filter
Organization: AT&T Bell Laboratories

In article <frazier.694462331-at-oahu> (Greg Frazier) writes:
>>Can a sponge be set up with a power head?
>Yes, they can.  There are some "power-sponge" filters which
>are sold with a powerhead (Eheim and Fluval both make these),
>but any good-sized sponge filter can be attached to a powerhed
>(We're currently using both a designed power-sponge and a homemade).

While it is true that a powerhead can be attached to a sponge filter designed
for air, I wouldn't reccomend it for a few reasons. First off, most of the
sponge filters that are sold are a very fine pore material. This clogs 
pretty quickly when run with an air pump, but even faster when powered by 
a powerhead. A powerhead will also make the gunk go pretty deep into the 
sponge, without too much hope of ever getting it out again. The sponge will 
begin to collapse on itself, and I think that the water runs through channels
in the sponge after a fairly short time (when used with a powerhead). 
The Tetra PHAS filters (Power Sponge Filters) have the same problem, although 
the sponge is larger, so it will take more time. 

I've used sponge filters for many years, with air and powerheads, and now I 
am convinced that the sponges that are sold have pores that are too small.
I have made a few sponge filters (from PVC, a powerhead of appropriate size, 
and an Large Aquaclear sponge (about $3.50), or a fluval sponge) and these 
work much better, and last much longer than the others. I don't think 
that these would be appropriate in a fry tank, or a tank with very small 
fish, but a powerhead would probably not be appropriate in these tanks anyway.
You COULD put a nylon stocking over the sponge to keep out fry and real tiny 
fish if you needed to, just make sure that there isn't too much water movement
for these fish.

The sponges mentioned (Fluval and Aquaclear) are coarse enough that they do 
not clog easily, and most of the gunk washes out. I have one that has not been
cleaned in over 3 months, and the flow has not diminished at all. 

There is one problem with these sponges, however, and that is making the hole.
I like to soak the sponge in water, then freeze it and use a drill to make 
the hole. I could also use a knife on a (thawed) sponge, but this is usually
pretty ragged.

>>stay clean, but now I see the sponge - heads say 'mechanical and
>>biological filtration should take place together'. Is this the current
>Sounds like advertising hype.  After all, you *can't* separate
>the bio and mech filtration on a sponge - so why not claim that
>that is the best way to go? :-)
>Actually, there is the benefit that you will have lots of little
>thingies living in your sponge that fry enjoy, should your fish

Just make sure that there isn't too much turbulance for fry.

Copyright 1991 All right s reserved  |J. DeRosa
Permission for reproduction in printed media or by           |AT&T  Room 1B32
Pay-for-read services explicityly disallowed. Permission     |100 Atrium Drive
is granted for reproduction by USENET & like free facilities |Somerset, NJ 08873

Jim Hurley -->  ...!ames!ultra!jimh  (408) 922-0100
Ultra Network Technologies / 101 Daggett Drive / San Jose CA 95134

New to list...lotsa Q's...

by Ken Laidlaw <K.Laidlaw/>
Date: Tue, 13 Jan 1998
To: apisto/

> > > Also, what be an adequate filter? I've used Aquaclear Minis in the past
> > > and liked them.

My preference is for air driven filters.  Either a sponge 
or box filter.  The sponge is good when you have fry as 
they will graze the sides for whatever is edible on there.  
Box filters are good for putting peat in.  I trap some peat 
between a top and bottom layer of filter floss.

You may have a risk of fry being sucked into a pump driven 
filter.  You could fit a nylon stocking over the end but 
this will prevent it from filtering large particles from 
the water.

 Thanks for the recommendation. So I should look for 1.1 Apistogramma
> cacatuoides? I've researched these at The Krib. I'll have to see if my
> LFS carries them. If not, are their any others I could consider keeping
> in my 1o gallon?

Other fish I have kept and thought easy were A. borellii & 
A. trifasciata.  If you wish to consider something other 
than Apistogramma then Nannacara anomala is a nice fish and 
very easy to breed.  Moving the male after spawning is a 
must though in my experience.

> Thanks George! I've been visiting The Krib a lot lately for info on
> Dwarf Cichlids. 

Also look at David Soares page which is


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