For me the first tank just looks so bare or myabe better choice of words is unfinished. Because it has enough Discus in it. But without a background and no substrate, it seems unfinished.
The second tank pictured looks more pleasing for my taste because theres a substrate, making the tank look fuller, even the plants look fuller, yes I know the second tank is much smaller but it looks more complete even though it too doesn't seem to have a background. It still looks far more complete than the first.
But heck this is only my opion of what I like and look for in aquariums containing fish, when a tank has no substrate I expect to see turtles in it. I'm not sure why everyone has a problem with having a substrate. Shoot I presently use the substrate in my 180g tank as that tanks filter medium.
Cheers pufferpunk, the plants have not grown yet ,weve just moved house thats why its a bit bare,il find apic from when they were in the six ft tank,here you go,not brilliant pics but you get the idea
I didnt make the tank and i bought the doors from a diy store but the rest is my own work,im a sheet metal worker so the stainless was easy and the two stands and two lids
If you are trying to grow out juveniles then you might want bb so its cleaner. If your discus aren't too small then you should be ok with either. If you have pigeon bloods then you might want to use a lighter color substrate and background to minimize the peppering (if you decide to go in that direction).