XS Filter Cartridge Replacement Options

[Shane L.]

Hello. I have a very small Koller internal power filter on a 3 gallon cylinder acrylic aquarium. It uses Tetra XS filter cartridges that are around 2” high x 2” wide x 1/4” thick and are basically a thin filter mesh with a little bit of charcoal inside. See attached photo of filter and cartridge. I have guppies, a few anubias, java moss and water sprite in the tank with driftwood, dragon stone and coarse gravel. From what I’ve read online, the charcoal is useless. Given the small size of the cartridge area of the filter and my 3 gallon tank, what would be the best replacement media to use in such a small filter compartment: Fine sponge, medium sponge, coarse sponge, crushed lava rock in a bag, filter floss, other - or just keep using the Tetra XS cartridge?  Keep in mind the total area of the compartment is only 2” x 2” x 1/4”. I’ve found tons of filter alternative options for large filters, but I haven’t been able to find any for such a small size. Any suggestions would be appreciated (but keep in mind, at this point I’m keeping this filter and not looking for alternate filter options such as a bigger one or an in tank sponge filter, etc.), I’m just looking for media alternatives. Thanks!

[Guppy Guy]

Wow! that’s small. Check out this video from the coop on optimizing Hang On Back filters.
Since it is so small, I would go with something like an aqua clear sponge cut to size, with a small prefilter sponge on the intake. It’s $10 up front, but you just squeeze it in aquarium water to clean it, so it will last way linger then the original cartridges. They also grow more beneficial bacteria.

 

[Shane L.]

On 9/22/2021 at 1:33 PM, Guppy Guy said:

Wow! that’s small. Check out this video from the coop on optimizing Hang On Back filters.
Since it is so small, I would go with something like an aqua clear sponge cut to size, with a small prefilter sponge on the intake. It’s $10 up front, but you just squeeze it in aquarium water to clean it, so it will last way linger then the original cartridges. They also grow more beneficial bacteria.

 

Thanks for the reply! Since I basically only have enough space for one layer, you are probably right. Sponge would make the most sense because it would filter out larger particles but also can be reused to keep beneficial bacteria, even though it's tiny. 

[Guppy Guy]

Just now thought of this, but you cold also use an aquarium co op sponge filter. They are cheap, easy to use, are great filters, and are easy to clean. The only other thing needed is an air pump, and for your tank, those are under $10. 

Sponge filters are also a favorite by many people. I took a pole awhile back, and sponge filters won by at least 30%

Edited September 28, 2021 by Guppy Guy

[Shane L.]

Thanks. My tank is very small at 9" diameter and about 12" tall, so not much room on the substrate, especially with the plants/rocks/wood we have in it. I didn't realize Aquarium Coop carried small/nano sponge filters though so I may look into that. Problem is the cylinder aquarium "magnifies" everything in it so it may make even the small sponge filter look huge. At least the internal power filter isn't very visible when viewing the tank. See attached photo for reference.  So far the Tetra filter cartridge seems to be working fine and water stays clear. But we'll see how that goes in a month or so when I run out of filter cartridges and need to decide whether to buy more, switch to foam or change to something else. 

[Odd Duck]

On 9/28/2021 at 1:20 PM, Shane L. said:

Thanks. My tank is very small at 9" diameter and about 12" tall, so not much room on the substrate, especially with the plants/rocks/wood we have in it. I didn't realize Aquarium Coop carried small/nano sponge filters though so I may look into that. Problem is the cylinder aquarium "magnifies" everything in it so it may make even the small sponge filter look huge. At least the internal power filter isn't very visible when viewing the tank. See attached photo for reference.  So far the Tetra filter cartridge seems to be working fine and water stays clear. But we'll see how that goes in a month or so when I run out of filter cartridges and need to decide whether to buy more, switch to foam or change to something else. 

Beautiful little tank with very nicely to scale plant selection!  I can’t quite make it out, is that Java moss or some Fissidens nobilis on the branch on the left?

I would also recommend cutting a piece of medium to coarse sponge to fit inside the filter. If you can rig it with a piece of coarse filter as a prefilter, that would be ideal.

Wow!  Just watched the video on cleaning it.  That’s a weird design and far more difficult to clean than it needs to be.  Might work great, I don’t know, but that’s a lot of disassembly and reassembly for something that doesn’t have to be that complicated.  It does look like a good quality plastic unlike the very brittle plastics some manufacturers use.  I just think it might be a bit too clever to be practical.

I still couldn’t tell exactly where the intake is - I see the tube intake into the pump, but I don’t see exactly where/how the water flows into that tube.  Is that sticking down directly into the water or down into a sort of catchment compartment that has a slot or grid that allows water flow into the body of the filter?

If it sticks directly into the water, you should be able to use the smallest sponge prefilter from the ACO - easy.  If it goes into a catchment area, you’d have to figure out how to fit a piece of sheet sponge or floss sheet into that area so it covers the slot or grid and still allows reassembly.  That might be trickier than is worth the hassle.

I’d be interested to see the opening that allows water in next time you take apart the filter for cleaning.  Yep, fully nerm, that’s me.  👋🏻

[Shane L.]

Thanks so much for the complements on the tank. It’s my first tank in about 32 years and my first shot at using live plants so I kept it simple with low light, no fuss plants. It is java moss on the spiderwood and attached to the dragon rock in a few spots. Then a few anubias nana petite. And water sprite in the back that I hope will fill in that space more.

Regarding the filter, the video on Youtube shows a slightly different version than what I have - mine doesn’t have the long intake tube shown on the video, and it seems it has much less area to intake the water than mine. I’ve attached a few photos with the filter out of the tank and top off so you can see the intake area. You can see there really is very little space for any filter media - just a little slit in the back. No intake tube. The water comes through the vents in the back which are right below the water line (it almost butts up against the side of the aquarium). Once the water goes through the vents, it then goes directly through the media, into the motor chamber area and out 3 little holes in the front that hit a baffle to make it trickle down into the water.

[Odd Duck]

On 9/28/2021 at 7:47 PM, Shane L. said:

Thanks so much for the complements on the tank. It’s my first tank in about 32 years and my first shot at using live plants so I kept it simple with low light, no fuss plants. It is java moss on the spiderwood and attached to the dragon rock in a few spots. Then a few anubias nana petite. And water sprite in the back that I hope will fill in that space more.

Regarding the filter, the video on Youtube shows a slightly different version than what I have - mine doesn’t have the long intake tube shown on the video, and it seems it has much less area to intake the water than mine. I’ve attached a few photos with the filter out of the tank and top off so you can see the intake area. You can see there really is very little space for any filter media - just a little slit in the back. No intake tube. The water comes through the vents in the back which are right below the water line (it almost butts up against the side of the aquarium). Once the water goes through the vents, it then goes directly through the media, into the motor chamber area and out 3 little holes in the front that hit a baffle to make it trickle down into the water.

Got it.  That looks like a much better design.  Much more simple and straightforward.

I think you could find some foam that’s thin enough to shimmy into that space.  Then it’s just a matter of using the current filter “cartridges” as a template to cut to shape.  Look for something that is about 30 ppi (pores per inch) to be fine enough to protect your pump but big enough to not clog too quick.  The ACO filters are, I think, 20-25 ppi and they would probably be too porous for such a thin piece of foam.  You might even be able to use the bilayer, bonded, floss type stuff but you’d have to discard and replace that which doesn’t get you any long lasting biofiltration.

[Odd Duck]

I got this once, to see if it would work in some refillable cartridges I was trying at the time.  The fine is very dense, but the “coarse” would probably be about right for this.

This “coarse” is still what I would consider a moderately fine sponge, over 30 ppi, maybe close to 40 ppi?  They are about 0.5” thick (~13 mm?) so it looks like they would fit into the space.  They are stiff enough you could easily slide them into the space once cut to size/shape.

[Shane L.]

On 9/28/2021 at 9:16 PM, Odd Duck said:

I got this once, to see if it would work in some refillable cartridges I was trying at the time.  The fine is very dense, but the “coarse” would probably be about right for this.

This “coarse” is still what I would consider a moderately fine sponge, over 30 ppi, maybe close to 40 ppi?  They are about 0.5” thick (~13 mm?) so it looks like they would fit into the space.  They are stiff enough you could easily slide them into the space once cut to size/shape.

Yea, I'm pretty sure filter sponge is the route I'll go. Thanks for the 30 ppi tip.

[Odd Duck]

On 9/28/2021 at 8:28 PM, Shane L. said:

Yea, I'm pretty sure filter sponge is the route I'll go. Thanks for the 30 ppi tip.

Hope it helps.  I’d just do a like but I’m chronically ORD.