Eco-Complete substrate and cory catfish

[LughLamfada, posts: 15]

Hi all--

I just set up an Amazon biotope tank and used the black Eco-Complete planted aquarium substrate with the intention of covering it with a layer of pool filter sand for the cories. I have been told by my LFS however that the sand on top of the Eco-Complete will hamper its ability to pull nutrients from the water column into the substrate.

I've done a few forum searches around the internet and many people swear their cory cats are ok in Eco-Complete, but I still worry that it might be a little too rough for them. What do you all think? Should I put a layer of sand over it, or will they be ok? Perhaps I could just create a sandy area for them?

This site and this forum are the resources I trust the most when it comes to my catfish, so your input is appreciated.

[dw1305, posts: 331]

Hi all,

I have been told by my LFS however that the sand on top of the Eco-Complete will hamper its ability to pull nutrients from the water column into the substrate.

Change your LFS.

The ability of any substrate to retain and exchange nutrients is defined by its cation and anion exchange capacities (CEC/AEC), the actual ions held and exchanged will depend upon both the lyotropic series and the concentration gradient between the ions on the exchange surface and the ions in the water.

The only way that the sand could stop nutrient exchange occurring in the substrate was if it formed a totally impermeable barrier between the water column and the Eco-complete. Pool filter sand definitely isn't impermeable to water (or it wouldn't work as pool filter sand), and will have a negligible effect on water movement

I think more of a problem will be that the Eco-complete will end up on top of the sand over time whatever you do, as the sand is both smaller grained and denser.

Perhaps I could just create a sandy area for them?

You certainly could, and this may be the best option, although I don't think the Cories will have a problem with the Eco-complete, as it is light in weight and they will still be able to work over it during their natural behaviour. I would always keep Cories over sand, but my understanding is that barbel erosion relates to water quality rather than substrate roughness.

cheers Darrel

[apistomaster, posts: 4570]

I find EcoComplete to be suitable for use with Corydoras although I prefer a thin layer of fine sand or thin layer of FloraBase by Coralife.
FloraBase is made up of rounded particles and is low in density so Corys may easily root through it without causing any abrasion injuries to their barbels. I recommend avoiding substrates with fractured faces with sharp edges. EcoComplete has rounded edge particles.

[LughLamfada, posts: 15]

Thanks for the input gentlemen. I siphoned up the Eco-Complete where I didn't intend to put plants, then put the tube into a bucket containing the pool sand and distilled water and just siphoned the sand onto the bottom. The result is Eco-Complete along the back and sides of the tank with sand in the middle. Looks great and the catfish are happily rooting around in it.