not seen this listed... under gravel filter "blanket" for fine sand???

[Magnum Man]

so as I start up some of my old aquariums, thinking about making them more Cory friendly ( never really had Cory's before, now I have 4 varieties ) anyway I am kind of partial to under gravel filters, about half my tanks still have them... I'm wondering if a very fine mesh or synthetic fabric could be used over the under gravel filter plates with a fine soft, more Cory friendly sand on top... most of my 80's filter plates have fairly wide slots for water movement, I'm concerned that even with play sand, that the granules will lodge in the slots, blocking flow, or worse yet, fall through the slots... & plug under the filter plate... thoughts ???

maybe no under gravel filter for Cory tanks???

 

[Sgooosh]

so as I start up some of my old aquariums, thinking about making them more Cory friendly ( never really had Cory's before, now I have 4 varieties ) anyway I am kind of partial to under gravel filters, about half my tanks still have them... I'm wondering if a very fine mesh or synthetic fabric could be used over the under gravel filter plates with a fine soft, more Cory friendly sand on top... most of my 80's filter plates have fairly wide slots for water movement, I'm concerned that even with play sand, that the granules will lodge in the slots, blocking flow, or worse yet, fall through the slots... & plug under the filter plate... thoughts ???

maybe no under gravel filter for Cory tanks???

i think that water will not flow through the sand as fast as in a gravel setup, so i would not do under-gravel.
the issues of sand getting stuck are also good points

 

[Fishmanic]

Facts:
Cories prefer sand
UG filters dont work well with sand substrate

Conclusion: one of them must be removed

 

[Colin_T]

It doesn't work, I tried it
I had undergravel filter plates over half the tank and sand over the other half. I used a glass strip to keep the sand and gravel separate. The gravel was on the filter plates and the sand was on the other side of the tank.

You can use a kitty litter tray (shallow plastic tray about 16 x 12 x 3 inches) filled with sand and put in the tank. The Cories use it as a sand pit. Then just have smooth gravel over the undergravel filter plates.

 

[Magnum Man]

Was actually thinking like slipping the whole plate in a led of pantyhose ( or similar ) and running a thin, maybe 1/2 to 1 inch layer of sand over the whole bottom, on top of the “blanketed” filter plate… the nylon material could even be stretched across the outlet holes, and the lift tubes just slipped over

 

[Uberhoust]

Why not use landscaping fabric. You will need a large surface area under the sand the UGFs I am familiar with would not have enough holes in the plates. Also if you use a meshed/sieved/sorted sand like pool filter or silica blasting sand then the water flow would be higher. Pool filter sand is selected primarily because it needs to allow water to travel through it. If you used un-sieved sand, like play sand, I suspect the fines will plug up most channels through the substrate. Both pool filter and silica blasting sands are relatively in expensive, just make sure the grains are at least sub angular. It would be an experiment. Nylon hose material is not very robust, you can leave it outside and use the damage on it as an indicator of pollution in the air.

 

[Magnum Man]

I did not know if landscaping fabric would be safe for aquarium use… it should be safe for the “environment” but I wasn’t sure if it was safe for underwater use in the aquarium???

 

[Uberhoust]

Landscaping fabric might not be safe for use if it has added compounds like anti fungal treatment, but I believe most are not treated. Laguna uses landscaping fabric for their float pond pots see https://www.lagunaponds.com/product-category/planting-2/ I have a couple of these in my outdoor ponds and they haven't caused any issue. You might be able to get one of their planting bags and use that material for your filter. (Edited) I believe most landscape fabric is made of polypropylene, it is a major plastic used for all sorts of food and water type applications, I even have some in my hip now.

As an experimenter, you will have to accept a certain amount of risk . I usually heavily rinse anything that goes into my tank. All the fabrics and plastic parts have a small amount of manufacturing oils, and mold parting compounds on the parts (waxes that allow the separation of the part from the mold)

 

[Sgooosh]

It doesn't work, I tried it
I had undergravel filter plates over half the tank and sand over the other half. I used a glass strip to keep the sand and gravel separate. The gravel was on the filter plates and the sand was on the other side of the tank.

You can use a kitty litter tray (shallow plastic tray about 16 x 12 x 3 inches) filled with sand and put in the tank. The Cories use it as a sand pit. Then just have smooth gravel over the undergravel filter plates.

yep! theres this pile of lava rock in the center of my tank, and the cories only stay in the outside part with sand or the rocks covered with moss

 

[TwoTankAmin]

What makes a UGF or RUGF works is because the proper size and dept of gravel make it the biggest potebtial bio-film one can have. The depth is about 3 inches and the gravel needs to be on the smaller side. I used an RUGF (which started as a UGF). I pulled it out when I discovered panda cory and swordtail fry under the plate. I gave up the RUGF as well because I was staring with live plants. It is hard to keep substrate ferts in the substrate with an under gravel system.

Modern science has given us a better way to do filtration with massive volume than a gravel bed UGF. It is called the Hamburg Mattenfilter and when used with a high quality, semi-rigid foams with well controlled porosity, it is the best filter I have found. The foam I use is the Poret, sold by Swiss Tropicals. I also use the foam in canisters and power filters. I even use the 10 ppi foam for pre-filters.

 

[Back in the fold]

Yeah ! what @Uberhoust said about that landscape fabric . Water will percolate through but sand won’t . I was going to say quilt batting like used to go in box filters but the landscape fabric idea is a winner all around . I like undergravel filters - always have .