Calling Netmax... Fluval 404 noise problem

[bannor]

Netmax,

I know you almost swear by these filters... I have one that is about 3
months old... keeps sucking air in somewhere... cycles about a minute
or so apart... gets noisey, then spits out a bunch of air bubbles...
if I rock the filter I can hear them being spit back out again and
after a few minutes of rocking it back and forth the noise stops for a
little while anyway... then the whole process starts again.

I have used silcone lubricant on the only "O"ring that came with the
filter but I actually think the air is coming in from elsewhere. More
than I can account for by ingestion from the intake. I do have lots
of very very tiny bubbles generated by a bio-wheel Hot Magnum Pro
filter on the same tank but these bubbles are very tiny and I seldom
see them actually making the trip to the far side of the aquarium
where the intake for the 404 is.

IE: intake for 404 is in far left back corner of 4 ft tank, bio-wheel
is about 3 horizontal feet away and 18 inches up on the back wall.
(actually on the top rim, but I am subtracting the gravel layer from
the total height of the tank. The output of the 404 is actually
behind the bio-wheel output, which is a waterfall type output that has
plastic extending about 1.5 inches below water level, so the 404
output nozel rests completely behind this 'plastic' wall and is
directed to the right hand corner... thus giving me fairly good round
the tank circulation.

The tank is very highly oxygenated... 3 airstones... so there are
those small bubbles floating around, just not very many by the intake
of the 404...

shoot... I don't think I can describe it any better... the top locks
down like it is supposed to... could it be the little hand-pump primer
on the 404? That doesn't seem to have any sort of tight fitting "O"
ring around the plunger, could the air be coming in there?

Obviously, I can't test it with soapy water since that would cause the
soap to be ingested into the filter.
Any suggestions?

[NetMax]

midposted..

"bannor" <bannor -at- echoes - net - mind the spam block> wrote in
message ...
> Netmax,
>
> I know you almost swear by these filters... I have one that is about 3
> months old... keeps sucking air in somewhere... cycles about a minute
> or so apart... gets noisey, then spits out a bunch of air bubbles...
> if I rock the filter I can hear them being spit back out again and
> after a few minutes of rocking it back and forth the noise stops for a
> little while anyway... then the whole process starts again.

A few years ago, the Eheim classics were my favorites, today it's the
Fluvals, because of what I liked in their last round of design changes
(and the amount of time I've logged with them). In a year or two, it
might be someone else, if they can do as good a job (or better) at a
lower price (I'm a bit frugal ;~). My loyalty gets won by design
features & prices, so today, imo Fluval has a great product. I don't
publicize who I work for, so my loyalty can move to whatever I think
presents the best value at any given time, and sometimes it's something
my competitors have and I don't :o(

> I have used silcone lubricant on the only "O"ring that came with the
> filter but I actually think the air is coming in from elsewhere. More
> than I can account for by ingestion from the intake. I do have lots
> of very very tiny bubbles generated by a bio-wheel Hot Magnum Pro
> filter on the same tank but these bubbles are very tiny and I seldom
> see them actually making the trip to the far side of the aquarium
> where the intake for the 404 is.

I don't think the airstones are a problem. I had an overstocked
Angelfish tank which I needed to increase the oxygenation, so I added an
airstone under the intake of a Fluval 304 (or 404, I can't recall the
model, it's been a while since I serviced it). The filter sucks the
airbubbles in and shoots them out, vastly increasing the oxygenation and
breaks up the surface protein layer. I haven't noticed any change in the
filter's noise or operating efficiency. I was actually surprised that it
seemed to make so little difference to the filter, as older versions of
canisters would suffer badly from operating this way. Air entrapment
used to be a big problem. I don't recommend you intentionally do this,
but you should be aware that it can be done with no apparent
consequences.

> IE: intake for 404 is in far left back corner of 4 ft tank, bio-wheel
> is about 3 horizontal feet away and 18 inches up on the back wall.
> (actually on the top rim, but I am subtracting the gravel layer from
> the total height of the tank. The output of the 404 is actually
> behind the bio-wheel output, which is a waterfall type output that has
> plastic extending about 1.5 inches below water level, so the 404
> output nozel rests completely behind this 'plastic' wall and is
> directed to the right hand corner... thus giving me fairly good round
> the tank circulation.
>
> The tank is very highly oxygenated... 3 airstones... so there are
> those small bubbles floating around, just not very many by the intake
> of the 404...
>
> shoot... I don't think I can describe it any better... the top locks
> down like it is supposed to... could it be the little hand-pump primer
> on the 404? That doesn't seem to have any sort of tight fitting "O"
> ring around the plunger, could the air be coming in there?
>
> Obviously, I can't test it with soapy water since that would cause the
> soap to be ingested into the filter.
> Any suggestions?

Everything upstream of the impeller is negative charged, so that would be
the area of interest. Everything after the impeller would be positively
charged, so any leak would manifest itself by weeping water. My guess
would be that the adapter which the hoses connect to, might be the
culprit. Check where the adapter connects to the motor head. Perhaps
one of the two gaskets has been damaged or is missing, or some foreign
material is across where the gasket sits. A drop of methylene blue in
that area might show the problem, but I'm guessing as I've never
encountered this situation before.

At my store, I don't carry replacement parts for the new Fluvals (it
hasn't been a necessity, knock on wood), but when the need arises, I just
take the parts I need off of a new filter from the shelf. I then order
the parts needed (1 week turn-around) and replace them so the filter can
be sold again. The biggest problem with all the filter brands is missing
parts, rather than defective parts. If your filter is new, then see if
your LFS can do the same thing. A filter is not something you want to be
without while waiting for parts. You can also try swapping only your
adapter module, but from a manufacturing perspective (I was a
manufacturing engineer in a previous life ;~), the tolerances are harder
to control on a larger plastic assembly, than on the smaller adapter, so
if no obvious problem is seen, then an out-of-round condition would more
likely be in the motor head where the adapter module snaps in.

It might vary by district, but where I am, Hagen (& Marineland) reps are
very good about replacing components. They don't even ask me for sales
receipts *shhhh* ;~). We are doing them a favour, protecting their
reputation by quickly fixing any problems which arise, so they are more
than happy about replacing the parts we used. If your LFS doesn't solve
your problem, go elsewhere and/or contact the rep directly. My advice is
the same for any manufacturer. Aquarium products (especially filters)
are critical components keeping your livestock alive. Don't settle for
defective operation from anyone. Let me know how it turns out.

NetMax

[bannor]

On Tue, 17 Feb 2004 20:41:50 -0600, "Rick" >
wrote:
<snip>
>> Obviously, I can't test it with soapy water since that would cause the
>> soap to be ingested into the filter.
>> Any suggestions?
>
>
>I'm not NetMax however my .02 would be to shut off you air stones and other
>filter for 15 minutes or so and see if the situation clears up, if so then
>you know the filter is sucking in air. Double check the connections at the
>disconnect. I have the same filter and if it wasn't sealing properly around
>the 0 ring then it would likely leak, a problem I went through with my 404.
>
>Rick
>

Thanks Rick... I tried that but it didn't seem to make a difference...
I left the air pump and the hot magnum turned off for about 45
minutes... didn't want to go longer so I wouldn't kill the bacteria...
anyway, no luck... pump still sucking air

[bannor]

Mid-posted back...

On Wed, 18 Feb 2004 19:56:23 -0500, "NetMax"
> wrote:
>midposted..
<snip>
>A few years ago, the Eheim classics were my favorites, today it's the
>Fluvals, because of what I liked in their last round of design changes
>(and the amount of time I've logged with them). In a year or two, it
>might be someone else, if they can do as good a job (or better) at a
>lower price (I'm a bit frugal ;~). My loyalty gets won by design
>features & prices, so today, imo Fluval has a great product. I don't
>publicize who I work for, so my loyalty can move to whatever I think
>presents the best value at any given time, and sometimes it's something
>my competitors have and I don't :o(

That makes sense to me. As I have stated previously, I have a 303 and
now a 404... the 303 works just fine, no noise what-so-ever and does a
great job of cleaning the water. This is my first experience with the
404 and I was not too sure I liked what I got. Seems that the design
needs a little improvement. The intake and output, being tied
together at the top, the 'first' filtration being sponges down the
left side, then supposedly under the baskets and back up to the
impeller... my only real complain is that the section that holds the
baskets is compley open all the way down to the bottom... if the water
flow was go through both sides of the sponge before entering the
basket area and only allowed access to that area via the bottom of the
basket stack I think it would ensure no by-pass. When I have opened
the filter, 4 times since installation, I have noticed a large amount
of particles that should have been stopped by the sponges had made it
all the way into all levels of the baskets... leading me to believe
that there is a large amount of filter by-pass in this thig.
<snip>
>I don't think the airstones are a problem. I had an overstocked
>Angelfish tank which I needed to increase the oxygenation, so I added an
>airstone under the intake of a Fluval 304 (or 404, I can't recall the
>model, it's been a while since I serviced it). The filter sucks the
>airbubbles in and shoots them out, vastly increasing the oxygenation and
>breaks up the surface protein layer. I haven't noticed any change in the
>filter's noise or operating efficiency. I was actually surprised that it
>seemed to make so little difference to the filter, as older versions of
>canisters would suffer badly from operating this way. Air entrapment
>used to be a big problem. I don't recommend you intentionally do this,
>but you should be aware that it can be done with no apparent
>consequences.
>
The filter handles the extra air just fine, it's just noisy.

<snip>
>> Obviously, I can't test it with soapy water since that would cause the
>> soap to be ingested into the filter.
>> Any suggestions?
>
>Everything upstream of the impeller is negative charged, so that would be
>the area of interest. Everything after the impeller would be positively
>charged, so any leak would manifest itself by weeping water. My guess
>would be that the adapter which the hoses connect to, might be the
>culprit. Check where the adapter connects to the motor head. Perhaps
>one of the two gaskets has been damaged or is missing, or some foreign
>material is across where the gasket sits. A drop of methylene blue in
>that area might show the problem, but I'm guessing as I've never
>encountered this situation before.
>

Ok... that paragraph started me thinking... I think I have found the
'air' leak. It is at the top of the quick-release, where in the
ribbed tubing just gets inserted into a rubber gasket... when I cut
the one piece tubing in half to install the tank, I did not shorten it
at all, just cut it in half and left the full length. This resulted
in an overly long intake tube path... this tube actually almost
completes a circle, thus hanging below the top of the filter. Anyway,
it seems that the extra weight of water in that section of the tubing
has pulled it slightly out of the rubber gasket. I thought I had
checked it all thoroughly, but I must have missed that the extra
weight might pull it loose. I am hesitant to shorten the tube since
my future plans for this filter are to move it to a 120 gallon tank
that I am slowly building DIY. Anyway, I just tied that section of
tubing up to the stands metal legs. I have an 18inch high, steel stand
with lots of scroll-worked metal. Has a neat curled section on the
back corner that I tied a support board to so that I could hold the
intake tubing above the filter which is now on the floor.
Fortunately, this back corner is actually in the corner of the room
and is completely hidden from view, so my Jerry-rigged tieback is not
visible unless you walk to that end of the tank and look behind it.

Anyway... that seems to have cut down on most of the air intake. I
will 'trim' the tubing this weekend when I do my next filter cleaning
and ensure that I have straight ends on it. I may shorten it by a
foot or so... more would not work with the plans for a taller tank and
stand.. Hopefully, when I get my plywood tank built this
spring-summer, and the stand and hood, I will not need to purchase a
longer replacement intake tube. I think I should be alright, since
the new stand will be 24 inches to 30 inches tall with a 24 inch tank
on top, So I will need about 5 - 6 feet of total length on the intake
tubing. All the wood is here, I just need some heat in the barn so
that I can start the constuction. Stand first, then tank, let sit
while I build the hood, then move the whole thing into the house.

>At my store, I don't carry replacement parts for the new Fluvals (it
>hasn't been a necessity, knock on wood), but when the need arises, I just
>take the parts I need off of a new filter from the shelf. I then order
>the parts needed (1 week turn-around) and replace them so the filter can
>be sold again. The biggest problem with all the filter brands is missing
>parts, rather than defective parts. If your filter is new, then see if
>your LFS can do the same thing. A filter is not something you want to be
>without while waiting for parts. You can also try swapping only your
>adapter module, but from a manufacturing perspective (I was a
>manufacturing engineer in a previous life ;~), the tolerances are harder
>to control on a larger plastic assembly, than on the smaller adapter, so
>if no obvious problem is seen, then an out-of-round condition would more
>likely be in the motor head where the adapter module snaps in.
>

SPeaking of which, it appears that the impeller well cover doesn't use
an "O" ring to seal but relies on the plastic molding on the well to
keep a seal... not real sure I like that part of the design, since
when it fails, the whole top will have to be replaced. Unless there
was a part missing? When looking over it 3 weeks ago, during last
pump maintenance, it did not appear that the well cover had any room
for an "O" ring... so I don't think anything is missing, just another
expample of a slightly poorer design. Of course, I have had to
replace my "O" rings on my 303 twice in 5 years from wear and tear. I
just hope that this 404 holds up better than that!

>It might vary by district, but where I am, Hagen (& Marineland) reps are
>very good about replacing components. They don't even ask me for sales
>receipts *shhhh* ;~). We are doing them a favour, protecting their
>reputation by quickly fixing any problems which arise, so they are more
>than happy about replacing the parts we used. If your LFS doesn't solve
>your problem, go elsewhere and/or contact the rep directly. My advice is
>the same for any manufacturer. Aquarium products (especially filters)
>are critical components keeping your livestock alive. Don't settle for
>defective operation from anyone. Let me know how it turns out.
>
I am not reall sure what you mean by 'reps' here. If you mean the
guys at the LFS, well, I purchased this filter online so I can't
really take it back.

Anyway, thanks for your suggestions... I think I found at least part
of the cause. I don't want to stain my filter with meth-blue at this
time, so I am hesitant to try using that to actually track down any
further air leaks. The pump is NOT leaking water anywhere so I can
deal with the noise if I have to.

[NetMax]

"bannor" <bannor -at- echoes - net - mind the spam block> wrote in
message ...
> Mid-posted back...
>
> On Wed, 18 Feb 2004 19:56:23 -0500, "NetMax"
> > wrote:
> >midposted..
<snip>
>
> Ok... that paragraph started me thinking... I think I have found the
> 'air' leak. It is at the top of the quick-release, where in the
> ribbed tubing just gets inserted into a rubber gasket... when I cut
> the one piece tubing in half to install the tank, I did not shorten it
> at all, just cut it in half and left the full length. This resulted
> in an overly long intake tube path... this tube actually almost
> completes a circle, thus hanging below the top of the filter. Anyway,
> it seems that the extra weight of water in that section of the tubing
> has pulled it slightly out of the rubber gasket. I thought I had
> checked it all thoroughly, but I must have missed that the extra
> weight might pull it loose. I am hesitant to shorten the tube since
> my future plans for this filter are to move it to a 120 gallon tank
> that I am slowly building DIY. Anyway, I just tied that section of
> tubing up to the stands metal legs. I have an 18inch high, steel stand
> with lots of scroll-worked metal. Has a neat curled section on the
> back corner that I tied a support board to so that I could hold the
> intake tubing above the filter which is now on the floor.
> Fortunately, this back corner is actually in the corner of the room
> and is completely hidden from view, so my Jerry-rigged tieback is not
> visible unless you walk to that end of the tank and look behind it.
<snip>

As you've discovered, the hose should not be cut in half, but rather at
the midpoint after installing the siphon and return pipe (or else they
would just sent you two pieces of hose ;~). I try not to have loops in
canister hoses, as it promotes air entrapment during start-up. I'm glad
I helped you find your problem, and that you can now correct it yourself.

cheers
NetMax

[bannor]

<snip>

>As you've discovered, the hose should not be cut in half, but rather at
>the midpoint after installing the siphon and return pipe (or else they
>would just sent you two pieces of hose ;~). I try not to have loops in
>canister hoses, as it promotes air entrapment during start-up. I'm glad
>I helped you find your problem, and that you can now correct it yourself.

Ok, I guess I missed something on the 'mid-point'. How do you
determine the midpoint? Do you connect both ends, then pull it
towards the filter to find this 'mid-point'... thinking about it, that
would make sense... wish I had done that when I installed the thing..

[NetMax]

"bannor" <bannor -at- echoes - net - mind the spam block> wrote in
message ...
> <snip>
>
> >As you've discovered, the hose should not be cut in half, but rather
at
> >the midpoint after installing the siphon and return pipe (or else they
> >would just sent you two pieces of hose ;~). I try not to have loops
in
> >canister hoses, as it promotes air entrapment during start-up. I'm
glad
> >I helped you find your problem, and that you can now correct it
yourself.
>
> Ok, I guess I missed something on the 'mid-point'. How do you
> determine the midpoint? Do you connect both ends, then pull it
> towards the filter to find this 'mid-point'... thinking about it, that
> would make sense... wish I had done that when I installed the thing..

Attach the hose to the intake pipe/strainer and position the intake pipe
in it's permanent location using the suction cup mounting base. Do the
same thing with the return pipe connected to the other end of the hose.
Position the filter in its permanent location under the tank. The hose
now hangs in a U over the filter. Cut the hose somewhere along it's
corrugated length (not the intermittent flat sections). Attach the
rubber adapters to the hose and connect to the adapter on the motor.

This always sounds so much more elaborate when describing it in text.
The pictograms in the directions do a much better job.
NetMax

[bannor]

Endposted for completion this time:

On Sat, 21 Feb 2004 01:03:14 -0500, "NetMax"
> wrote:

>
>"bannor" <bannor -at- echoes - net - mind the spam block> wrote in
>message ...
>> <snip>
>>
>> >As you've discovered, the hose should not be cut in half, but rather
>at
>> >the midpoint after installing the siphon and return pipe (or else they
>> >would just sent you two pieces of hose ;~). I try not to have loops
>in
>> >canister hoses, as it promotes air entrapment during start-up. I'm
>glad
>> >I helped you find your problem, and that you can now correct it
>yourself.
>>
>> Ok, I guess I missed something on the 'mid-point'. How do you
>> determine the midpoint? Do you connect both ends, then pull it
>> towards the filter to find this 'mid-point'... thinking about it, that
>> would make sense... wish I had done that when I installed the thing..
>
>Attach the hose to the intake pipe/strainer and position the intake pipe
>in it's permanent location using the suction cup mounting base. Do the
>same thing with the return pipe connected to the other end of the hose.
>Position the filter in its permanent location under the tank. The hose
>now hangs in a U over the filter. Cut the hose somewhere along it's
>corrugated length (not the intermittent flat sections). Attach the
>rubber adapters to the hose and connect to the adapter on the motor.
>
>This always sounds so much more elaborate when describing it in text.
>The pictograms in the directions do a much better job.
>NetMax

Thanks Netmax... I am one of those people that doesn't understand
'pretty pictures' very well I guess... I read and re-read the
intructions before I put the whole thing together and as I recall the
word 'midpoint' was mentioned more than once... it sorta got 'stuck'
in my mind so, of course, I spread the whole tube out, bent it in half
and cut it in the 'middle'. Oh well.

I went ahead and shortened the input tube section to remove the
'loop'. I also added a tie-back to hold the tubing in place to 'share'
the weight. I also re-cut the end to get a 'flater' edge which
allowed me to get more of the tube into the rubber gasket. This all
helped to some extent, but I am still getting air from somewhere. I
am going to the LFS to get some Meth Blue to try your first suggestion
of putting some around different junctions to see if I can locate
where the rest of the air is coming from. I'll just have to deal with
it I guess if I can't find it this way.

On a different note: Would it be advisable to place a thin sheet of
plastic down the inside of the filter between the baskets and the
sponges? Actually between the baskets and the inside edge of the
'slot' for the baskets? As I said, it looks to me like the water has
a free flow path down the edge between the sponge and the basket
chamber all the way down from the top to the bottom. I am seeing
plant matter that is fairly large (in compairson) that has somehow
made it past the input filter sponges and the media baskets. This
stuff is making it to all 4 layers of media so there is definately
some sore of water bypass going on.

Maybe I am just nuts... I was hoping that this filter would be better
than my 303... it IS larger, so there is more media space but the
water flow seems somewhat messed up.

Ex: v XX v <--- <---- vv | ^^
v XX v :_________|_()___
v XX v : > OOOOOOOO |
v XX v : > OOOOOOOO |
v XX v : > OOOOOOOO |
v XX v >>> ^^^^^^^^^^ |
____________________|


Sort of like that, where the semi-colons represent the opening between
the input filter sponge and the media baskets (capitol O). I mean it
looks like the water goes down BOTH sides of the double input sponges
and some of it can go directly into the media basket side of the
filter withough being forced to go through the sponges. Water
direction represented by either v ^ < or >. What I am proposing is a
thin sheet of rigid plastic from the top down to about 1.5 inches from
bottom to force the water to enter the media chamber from below.

From the physical properties of the media chamber etc, it looks like
the filter was originally designed to have the input entrance on the
left hand side, forcing the water through the pre-filter sponge then
down under the baskets and back up through them. However, when they
modified the input/output to compete with other manufacturors combined
inputs and outputs, they just moved the intake over to the center of
the pump thus missing most of the pre-filter sponges.
Any thoughts, suggestions or am I just attempting to fix something
that isn't really broken?

[NetMax]

"bannor" <bannor -at- echoes - net - mind the spam block> wrote in
message ...
> Endposted for completion this time:
>
> On Sat, 21 Feb 2004 01:03:14 -0500, "NetMax"
> > wrote:
>
> >
> >"bannor" <bannor -at- echoes - net - mind the spam block> wrote in
> >message ...
> >> <snip>
<snip>
> On a different note: Would it be advisable to place a thin sheet of
> plastic down the inside of the filter between the baskets and the
> sponges? Actually between the baskets and the inside edge of the
> 'slot' for the baskets? As I said, it looks to me like the water has
> a free flow path down the edge between the sponge and the basket
> chamber all the way down from the top to the bottom. I am seeing
> plant matter that is fairly large (in compairson) that has somehow
> made it past the input filter sponges and the media baskets. This
> stuff is making it to all 4 layers of media so there is definately
> some sore of water bypass going on.
>
> Maybe I am just nuts... I was hoping that this filter would be better
> than my 303... it IS larger, so there is more media space but the
> water flow seems somewhat messed up.
>
> Ex: v XX v <--- <---- vv | ^^
> v XX v :_________|_()___
> v XX v : > OOOOOOOO |
> v XX v : > OOOOOOOO |
> v XX v : > OOOOOOOO |
> v XX v >>> ^^^^^^^^^^ |
> ____________________|
>
>
> Sort of like that, where the semi-colons represent the opening between
> the input filter sponge and the media baskets (capitol O). I mean it
> looks like the water goes down BOTH sides of the double input sponges
> and some of it can go directly into the media basket side of the
> filter withough being forced to go through the sponges. Water
> direction represented by either v ^ < or >. What I am proposing is a
> thin sheet of rigid plastic from the top down to about 1.5 inches from
> bottom to force the water to enter the media chamber from below.
>
> From the physical properties of the media chamber etc, it looks like
> the filter was originally designed to have the input entrance on the
> left hand side, forcing the water through the pre-filter sponge then
> down under the baskets and back up through them. However, when they
> modified the input/output to compete with other manufacturors combined
> inputs and outputs, they just moved the intake over to the center of
> the pump thus missing most of the pre-filter sponges.
> Any thoughts, suggestions or am I just attempting to fix something
> that isn't really broken?

LOL, I wouldn't mess with it. I'm sure some bypass is desirable. The
bypass around the sponge prevents a clogged sponge from decreasing the
flow enough to kill any nitrifying bacteria in the media chambers. The
bypass around the media baskets prevents the nitrifiers in the sponge
from asphyxiating from a clogged media basket. Any type of a bypass
provides a more uniform flow rate (less variable to the media
restriction). Most filters have some bypass capability tucked away
somewhere. Offhand, only the Maxiflo and the Vortex have no bypass
capability that I recall seeing. If the perfectionist in you insists ;~),
tuck a piece of foam in between the pre-filter sponge and the top media
basket.

In the meantime, I'll FAX Fluval and tell them to put a deflector on the
input to throw the water to the far side ;~) If it's any consolation, I
used to always curse filters and I'd modify them to get them working
properly, but with the quality of the stuff available now, I almost don't
have to do a thing.

NetMax

[james mitchell]

> On a different note: Would it be advisable to place a thin sheet of
> plastic down the inside of the filter between the baskets and the
> sponges? Actually between the baskets and the inside edge of the
> 'slot' for the baskets? As I said, it looks to me like the water has
> a free flow path down the edge between the sponge and the basket
> chamber all the way down from the top to the bottom. I am seeing
> plant matter that is fairly large (in compairson) that has somehow
> made it past the input filter sponges and the media baskets. This
> stuff is making it to all 4 layers of media so there is definately
> some sore of water bypass going on.

If you pull (stretch) the 2 sponges closest to the media chambers up
slightly, you will eliminate most of this bypass path when the canister top
is in place.

The prefilter arrangement on the '04 series is pretty bizarre but it seems
to work well on both my units. If you look closely, the foam blocks are
spaced from the plastic which allows for many possible pathways through the
foam down to the bottom of the canister.

[bannor]

On Tue, 24 Feb 2004 02:11:50 GMT, "james mitchell" >
wrote:

>> On a different note: Would it be advisable to place a thin sheet of
>> plastic down the inside of the filter between the baskets and the
>> sponges? Actually between the baskets and the inside edge of the
>> 'slot' for the baskets? As I said, it looks to me like the water has
>> a free flow path down the edge between the sponge and the basket
>> chamber all the way down from the top to the bottom. I am seeing
>> plant matter that is fairly large (in compairson) that has somehow
>> made it past the input filter sponges and the media baskets. This
>> stuff is making it to all 4 layers of media so there is definately
>> some sore of water bypass going on.
>
>If you pull (stretch) the 2 sponges closest to the media chambers up
>slightly, you will eliminate most of this bypass path when the canister top
>is in place.
>
>The prefilter arrangement on the '04 series is pretty bizarre but it seems
>to work well on both my units. If you look closely, the foam blocks are
>spaced from the plastic which allows for many possible pathways through the
>foam down to the bottom of the canister.

That makes sense... I will try that on next maintenance...

Currently still getting some air into the filter from somewhere... I
will have to keep looking for the 'leak'. Otherwise, I am very happy
with the filter... it does seem to catch a large amount of the 'solid'
wastes from both fish and plants...