Welcome to FishLore! I might be wrong on this, but I have never read where either of those types of substrate would be better. I do know that a lot of the discus fanatics have bare bottom tanks, so they clean up easier since discus are so sensitive to water quality. I would think the sand would be harder to clean than the gravel.
I love DISCUS! I wish I had a big tank with Discus only. Perhaps one day
I agree with Gunnie. Sand must be much harder to clean than gravel. And if Discus are so sensitive to water chemistry, it's better to go with someting easy to clean. If you don't care about tank setup (i.e. how your tank looks), of course, bare bottom would be easiest to clean.
P.S. I am wondering: since Discus are so delicate, what water parameters are a must for them? Will they tolerate some nitrate or not even that? And how large and how frequent water changes are necessary for them?
Looks like Discus are a lot of work (but I wouldn't mind it if I could have Discus). Indeed they're unusually beautiful fish but considering that they need large tanks (I wouldn't get anything smaller than 75G for them) that makes an awful lot of water changes if performed every second day. And I assume these water changes are rather large too (at least 30% each time).
That would be very convenient Emma, only it wouldn't clean the gravel the way a human being can with a siphon tube. And there are always debris and fish waste accumulating on the bottom and contributing to degrading water quality - all of which need to be removed. And I don't know how else if not manually one could do this.
Regarding Discus and heavily planted tanks: I just realized that having a heavily planted tank for Discus has only advantages. That's because in heavily planted tanks there is also more plant matter decaying (which is a regular process - old leaves decay and new ones grow in their place). That decaying matter lowers the pH, which means a heavily planted tank can help keep a stable and acidic pH of water. Plus, plants clean water as well (the more plants the better in this respect).
I couldn't agree with you more... Having a bare bottom tank is fine in my opinion but the debris actually floats more easily as compared to having gravel... I actually have a planted, gravel aquarium for my discus... And they don't really need that big a space... I've seen breeder sized discus housed in 30 gallon aquariums...Ofcourse a bigger tank would be better but not necessarily if you were to house only 2 discus... But if you were to have more, 75 gallons would be ideal...