So im trying to create height in the aquarium and before i do this idea im just going to ask if people think it will work.

Im using egg box which is essentially what we use to create gravel driveways that allow the water to run through them. Ill be stacking these on top of each other (a lot like Dennis Wong does) the only difference is instead of filling the gaps between the egg box with soil or lava rock i was wondering if you think filling it with filter media sponge would be a good idea?

So this would basically take up any large air gaps in the crates and also it would be a good place for bacteria to grow and it would also allow a free flow of water between the substrates levels.

I will of course be adding lava rock and aqua soil mixed on the top two levels so the very bottom two levels (around 4" ) will be sponge in between the egg box.

The sponge will be holding no weight the egg box will do all that job. The sponge is just there to fill the gaps and to allow the substrate to sit on top without falling through.

Each level of egg box (2") has a grid within each hexagonal shape so each sponge depth is only going to be around 1.5" I was going to use a very fine sponge as this has a smaller and more dense structure.


The whole idea behind this is money saving on substrate basically and weight in the tank but still allow somewhere for bacteria to grow. I dont see the point in berrying decent substrate and allow it to compact at the bottom levels under rocks if i dont need it to. Over all height to the substrate level at the back will be aorund 7-8" in height then obviously large rocks on top.

Thoughts??

That should work fine, crushed lava rock would be better otherwise your substrate will just fall through the cracks gradually over time.

I have never tried what you are doing, and frankly I don't know what the egg box is that you are working with so I don't know for sure how that looks/goes together. But my gut says that using filter sponge in layers inside the tank is a bad idea. Filter sponge, even the course kind will compact very quickly with any weight ontop of it. All those nice open pores will close and you will end up with layers that will become completely impermeable in short order once the few remaining holes fill up with mulm/general debris.

I would stick with gravel for fill in simply because it will always have holes between individual pieces, they will never perfectly fit together. The gravel will grow bacteria just fine. I don't see any need for 10 inches of fertilized substrate either, inert lava rock or pea gravel in mesh bags is a pretty accepted way of gaining height in substrate without spending a fortune.

I think he’s talking about using drainage grates. There won’t be any compaction under them.



I’d just lightly wad up tufts of fiberglass window screen in the gaps. You need the fiberglass screen anyway to put on top of grates to keep substrate from falling in holes anyway. Just the dirt cheap stuff, no UV coatings etc. Simply a fiberglass mesh with pvc coating, stuff will last for decades and plenty of surface area.

https://www.homedepot.com/p/Saint-Go...SABEgKUlvD_BwE