I know this sounds retarded to ask, but can I reuse the black substrate my used fluval ebi tank came with? It is the black substrate the fluval ebi tank comes with in the box. It is meant to help plant growth and so forth. I really like the stuff but don't know if I can reuse it or not since the original owner did use it.
All help is appreciated!
Yes you can, just clean it really good. And once the tank is setup, just leave it empty (but running) for at least a week with the heater set high (86+ F). I actually recommend fully cycling it before adding any fish.
If you want to play it safe, just get the regular black gravel from the pet store.
For nutrients it may or may not be exhausted ... but who cares? Only substrate rooted plants (like Swords and Crypts) get any benefit from it. Non rooted (Java Fern, Anubias, Moss), stem (Wisteria, Brazilian Pennywort, Hornwort, etc), and floating (Duckweed, Water Sprite, Amazon Frogbit, etc) get absolutely nothing from the substrate. These plants require a liquid fertilizer as they assimilate their nutrients directly from the water column (and even substrate rooted plants benefit from liquid fertilizers). Heavy root feeders (Swords and Crypts) can benefit from an enriched substrate, but a root tab works even better.
Lots of folks are quite successful growing plants in regular old gravel or play sand that you buy for your kids sandbox. Here is an example of my 20g tank that has the resin coated gravel pet stores sell and have no nutrients what-so-ever.