A bottom of the tank Matten filter?

[gardenman]

The talk on "The Great Canister Filter Debate" of sponges and under-gravel filters got me thinking about combining a Matten filter type foam and an under-gravel filter grid to make a bottom of the tank Matten filter. No gravel at all. Put the UG filter grid down and then the foam atop it. You'd end up with lots of surface area for bacteria. A black sponge on the bottom of the tank wouldn't be horribly noticeable. You could even cut holes in the sponge for planters with plants if you wanted to. Maybe even apply a thin layer of substrate if desired. A quick google for "bottom Matten filter" didn't bring up much that was relevant. It would give you more biofiltration area than any conventional Matten filter. The UG filter grid would support it and allow water to flow through it. Am I missing something? This seems like something that would be pretty easy to do. Conventional Matten filters occasionally get fish stuck behind them where they can perish. A fish would be hard pressed to get under an under-gravel filter grid. It would be harder to remove to clean or service, but it's not like you'd have to do anything frequently. Does anyone know of anyone doing something like that? Am I missing an obvious negative to the idea?

[Beardedbillygoat1975]

I’ve never seen one. It’s a cool idea. As to why it’s never been tried really not sure. People put media underneath their ugf grids and there are tons of hotrodded ugfs and hmfs out there. I think it’s a cool idea and if you have the tank space and the will go for it. 
I’m not sure on which porosity I’d use as the sponge layer. It’ll be interesting to see what others think. 30 ppi is best for biological filtration and I’ve seen a lot of people use if for mattenfilter. 

[HH Morant]

I have never heard of or seen anything like that. You would want biological filtration but not mechanical, so that would mean 30 ppi foam or 20. I think 30 would be better because more food would stay on the surface rather than sinking down into the foam. Smaller pores (30 ppi) would probably look better.

It would be interesting to see if you have to remove it periodically to clean, I am not sure whether you would. I have read that under-gravel filters never need to be moved or cleaned. The less the beneficial bacteria is disturbed, the better, so you don't really want a "clean" filter of any kind.

If cleaning is necessary, seems that it would be easy. Just move the foam, let the detritus settle, and suck it out.

It might be difficult to find a way to have any kind of aquarium furniture. The weight of wood, rocks, or planters would compress the foam. Maybe you could find a way to do it by resting the furniture on the glass bottom and fitting the foam tightly around it.

It might be an interesting experiment.

 

[Beardedbillygoat1975]

@HH Moranti almost see this as an ideal breeding tank- if you put a barrier/screen above the foam with egg scatterers they’d just nestle into the foam and after hatch they’d have a load of biofilm and aufwuchs to feed on. 

[Odd Duck]

Very interesting to think about.  I would worry about debris eventually clogging the foam but if it was only a breeding tank or if there were shrimp to clean the foam, it would probably work.  Especially if all plants were in pots that could be moved so the filter could be cleaned between breedings.

[gardenman]

I think a gravel vac attachment could keep the foam clean enough. Java fern, and anubias might just root into the foam and not need a planter of any type. They grab onto rock and wood, so a porous foam should support them also. I think I might try it on my ten gallon tank. Amazon has 2" thick 40 PPI foam which might clog faster but would look more like a basic black bottom. I'd keep my sponge filter going simultaneously, then eventually shift to just the bottom Matten filter.

[Beardedbillygoat1975]

Plants and mosses would attach to the mattenfilter foam - how cool would a carpet of moss be on it?! Liking this idea more and more!

[Odd Duck]

On 11/24/2021 at 10:48 AM, gardenman said:

Java fern, and anubias might just root into the foam and not need a planter of any type.

They absolutely would root into foam.  I’ve had some grab onto sponge filters before and had to tear/break roots to get them loose to clean the filter.  Rooting plants into the foam I suspect would become problematic.  It would increase the clogging and make it harder to clean.

I do want to make a matten foam back wall someday covered with assorted epiphytes and mosses.

Edit to add I wouldn’t be using the matten as a filter, just as plant support so I guess it would no longer qualify as matten at that point. I haven’t been able to come up with a reliable way to secure the foam since I know silicone or glue of almost any type will eventually deteriorate since the foam deteriorates away from the adhesive in only a few years.

Edited November 24, 2021 by Odd Duck

[gardenman]

An easy way to secure the foam on a back wall would be to cut some egg crate to the size of the back then sew the foam to the egg crate using monofilament fishing line. It would be pretty easy to clip the egg crate in place.

I've ordered the foam and UG filter to give this a try. We'll see what happens. I'll try java fern, anubias nana petite, and some dwarf sag (maybe make a slit in the foam for the sag?) I don't see any way it'll hurt the fish, so I'll give it a shot and see what happens. The UG filter is blue, so if the front edge shows I may paint that visible part black first.

[Odd Duck]

On 11/24/2021 at 11:51 AM, gardenman said:

An easy way to secure the foam on a back wall would be to cut some egg crate to the size of the back then sew the foam to the egg crate using monofilament fishing line. It would be pretty easy to clip the egg crate in place.

Genius!  See this exactly is why I love this forum.  I need to put into words more often what I need and someone will get me an answer!

[Odd Duck]

On 11/24/2021 at 11:51 AM, gardenman said:

The UG filter is blue, so if the front edge shows I may paint that visible part black first.

If you remember to shift the UGF towards the back they are almost always enough smaller than the tank that they won’t show.  I used to use UGF for every tank but sometimes if you forget to hold it towards the back or started adding your gravel toward the back first, it would shift to the front and show.  I’d bet you could add just a few black pebbles at the front edge to force the UGF against the back wall (and maybe a few at the sides to center it), and that would keep it in place and shadow should take care of the rest if any was visible.

I’ve seen some black UGF plates but they were the kind with deep ridges, which is not my favorite, but that might be perfect for this use with filter foam as floor.

@gardenman I think I would need to find some black buttons to keep monofilament from eventually cutting into the foam when sewing it to the egg crate, but that’s a solid idea.  I think I have some large gauge expired nylon suture that would make this as easy (well, as easy as it can be).

Edited November 25, 2021 by Odd Duck
Typos

[Brandon p]

Check out shrimp matten  filter it looks to be quite similar to what you described .Maybe I don’t understand what you guys are saying, but what happens when everplant and moss grow roots in the the foam. How would you Clean it, how will you stop all of the roots from breaking on steamed plants and keeping the look of the tank intact. I use a ugf for my planted tanks just so the roots can grow in the empty space. I may not know all of the material you are taking about.  After watching the shrimp matten filter I think will work. I can’t find the very first video that showed the matten filter similar to the one you talked about but I can’t in went back and added the first line. I have a tank think should be here around the 20th of dec. and I may think about doing this are fairly course gravel. I would like to see if it works.

[Beardedbillygoat1975]

@Brandon pshrimp Mattenfilter and the Hamburg Mattenfilter etc they’re all the same thing. 

The plants would use the waste the beneficial bacteria in the mattenfilter break down. 

A lot of shrimp keepers put moss on the mattenfilter for the shrimp to hold on to and graze on plus it looks cool to have a good moss wall. Moss carpets are amazing and this one would be spectacular if it took root. 

[Fonske]

On 11/25/2021 at 12:48 AM, gardenman said:

Java fern, and anubias might just root into the foam and not need a planter of any type. They grab onto rock and wood, so a porous foam should support them also.

The patch of anubias nana petite below is rooted on a piece of 1" thick sponge.  Hope you can see it on the second photo more clearly.  There is also some moss self-attaching to the sponge (unlike the anubias, I didn't put the moss there). So yes, no need for planters with these plants. 

 

[Guppysnail]

I think it would work for quite awhile if you went with a high enough porosity. Although I am a die hard 30 ppi for biological and 20 for large mechanical I know they do clog eventually. Perhaps a bottom layer of coop coarse with sectioned layers of 30 ppi on top so the 30 can be lifted and squeezed out every so often. Just a thought. This thread made me think and gave me ideas thank you. I use terra cotta pots with bare bot tin several of my tanks. The pots sometimes get knock over (by me 🙃) the gravel spills out. I’m going to replace the gravel with extra matten filter media I have. I love the way this forum Spurs creativity 😁. Best of luck I hope this is very successful for you. You may be onto the next best thing. 

[gardenman]

The foam I ordered is 2" thick and 40 PPI which is quite dense and will clog more easily, but I think using my gravel vac over it should unclog it fairly easily. The foam density should keep most of the debris on/near the surface and easily vacuumed away. Java fern and Anubias nana petite can make an attractive planted tank on their own. I've got lots of dwarf sag also, so I'll try a piece or two of that in there also. I don't know how the sag runners will do in foam, but I've got the plants, so it won't cost me anything to find out. As to decorations depressing the foam, the only things I'll be putting in will be pleco caves and a piece of driftwood, and they're quite light. I'm planning to cut the foam a bit oversized to get a nice tight fit. I'll add some of my java moss also to see how it does. I'll likely use a small stone to hold the plants in place until they root into the foam. (Assuming they do root into the foam.) I'm not risking the fish at all because I'll still have my current filtration (a sponge filter and small HOB) going for a while. Once I'm moderately comfortable the bottom Matten filter has had a chance to mature (5-6 weeks), I'll move the sponge to another tank and keep it running but trust the Matten filter to take over. If things start to go bad, I can plop the sponge right back in. I may keep the small HOB running for mechanical filtration even with the Matten. 

I like a black substrate and black foam as a substrate and Matten filter combined intrigues me. The filter will arrive tomorrow, but the foam is still a week to ten days out. Once it comes, I'll tear down the tank and rebuild it with the DIY bottom Matten filter in place and we'll see what happens. It'll have about twice the surface area of a conventional ten-gallon Matten filter. Biofiltration shouldn't be a problem once it's established. It'll have two airlift tubes (according to the illustrations) so water flow should be comparable to a "normal" Matten filter if not better. I'm a little intrigued by the idea of backflushing the filter during water changes by pouring the fresh water in through the airlift tubes. A piece of soft plastic tubing with an outer diameter about the size of the inner diameter of the airlift tubes and connected to a container (plant watering pitcher?) held well above the tank for pressure could backflush the Matten filter. (Assuming it didn't just lift and float the filter.) You'd have to plug the second airlift tube also. Lots of fun stuff to play with and experiment with using this concept.   

I still don't see any big red flags, so we'll see what happens. It's about a $25 investment and if it works, it'll be a good return on the investment. At worst I have some foam to use for other things and a new UG filter.

[Guppysnail]

I have a tank with just anubias and ferns. I like the look. I hope you take pictures of your build. If this works I would not mind trying it out myself. 

[Odd Duck]

The more I think about all this the more interesting it gets.  Especially for use with shrimp.  I’ve been planning to reset some shrimp tanks anyway, but was planning a thin layer of sand.  This makes me rethink the sand.

I’ve got some thin pieces of foam that I could stick some Anubias, Java ferns, or Buces to and let them root.  I don’t know if I want to cover the whole bottom, but almost use them like planters like @Fonske did.  It would still provide plenty of “picking” territory for shrimp.  

[gardenman]

I can't really find a negative but it seems like such an obvious thing to do that I keep thinking there must be something I'm missing. People put Matten filters on back walls, side walls, in corners, but I've never seen one on the bottom atop an under gravel filter plate. It seems like an obvious way to do it once you associate the foam and UG filter. Maybe no one's done it because UG filters aren't especially popular these days? Sometime next week the foam should arrive and I'll try setting up the tank and we'll see what happens.

[Torrey]

On 11/25/2021 at 5:54 AM, gardenman said:

I'm a little intrigued by the idea of backflushing the filter during water changes by pouring the fresh water in through the airlift tubes. A piece of soft plastic tubing with an outer diameter about the size of the inner diameter of the airlift tubes and connected to a container (plant watering pitcher?) held well above the tank for pressure could backflush the Matten filter. (Assuming it didn't just lift and float the filter.) You'd have to plug the second airlift tube also.

I haven't ever used foam under my UGF, but I have set up biorings under UGF.

I have 'backflushed' by sliding the gravel vac over one uplift tube and clipping in place, and pouring water into the other uplift tube. I was concerned about potentially forcing something out of the UGF and into the water column that could be detrimental to the fish.

 

Looking forward to following your journey!

[gardenman]

On 11/26/2021 at 3:57 AM, Torrey said:

I haven't ever used foam under my UGF, but I have set up biorings under UGF.

I have 'backflushed' by sliding the gravel vac over one uplift tube and clipping in place, and pouring water into the other uplift tube. I was concerned about potentially forcing something out of the UGF and into the water column that could be detrimental to the fish.

 

Looking forward to following your journey!

I'm going to use the foam on top of the UG filter plate in place of substrate instead of under it. That way the tank water has to flow through the foam essentially making it a horizontal Matten filter on the tank bottom. The two inches of 40 PPI foam covering the tank bottom gives me enormous surface area for beneficial bacteria. The UG filter should pull water from the bottom of the tank through the foam, and then exhaust it higher up creating good flow in the tank also. It'll be an interesting experiment. The UG filter should arrive today. The foam's been shipped but is coming through the mail, so it'll be here whenever (1st-7th is suggested.) The foam is 23" X17" X2" so it'll need a bit of trimming. I'm planning to cut it a bit oversized (half inch larger?) for a snug fit. It may need a day or two to uncompress as most foam is shipped highly compressed these days. An electric carving knife does a good job cutting foam. Cut the foam to size, cut out a hole or holes for the uplift tubes of the UG filter, squeeze it into the tank, and then see what happens. I can't think of a reason it won't work. 

[Torrey]

On 11/26/2021 at 5:16 AM, gardenman said:

I'm going to use the foam on top of the UG filter plate in place of substrate instead of under it. That way the tank water has to flow through the foam essentially making it a horizontal Matten filter on the tank bottom. The two inches of 40 PPI foam covering the tank bottom gives me enormous surface area for beneficial bacteria. The UG filter should pull water from the bottom of the tank through the foam, and then exhaust it higher up creating good flow in the tank also. It'll be an interesting experiment. The UG filter should arrive today. The foam's been shipped but is coming through the mail, so it'll be here whenever (1st-7th is suggested.) The foam is 23" X17" X2" so it'll need a bit of trimming. I'm planning to cut it a bit oversized (half inch larger?) for a snug fit. It may need a day or two to uncompress as most foam is shipped highly compressed these days. An electric carving knife does a good job cutting foam. Cut the foam to size, cut out a hole or holes for the uplift tubes of the UG filter, squeeze it into the tank, and then see what happens. I can't think of a reason it won't work. 

I don't see any reason it won't work, either!

Can't wait to see the results.

[OnlyGenusCaps]

Glad you'll be trying this @gardenman!  I think it's a great idea, and I may give it a try on a fry or QT tank.

[gardenman]

On 11/27/2021 at 9:35 PM, OnlyGenusCaps said:

Glad you'll be trying this @gardenman!  I think it's a great idea, and I may give it a try on a fry or QT tank.

The UG filter came today. It's assembled and I'm waiting on the foam now. It's somewhere between here and Wisconsin. It should be here Wednesday or Thursday. I can't think of a reason this won't work, so we'll see what happens. I could be onto something here. I'm dusting off a bigger air pump to power both uplift tubes and the existing sponge. I think this will work out. It's about double the foam volume of a 'normal' Matten filter for a ten gallon tank. It should work okay. We'll see. It'll be four to six weeks before I know too much, but we'll start to learn a bit later this week.

[Brandon p]

Can you Journal the process