It's a bit more complex that this. A lot of fish, particularly cichlids and tetras, alter their colours depending on their environment. So if you keep kribs (for example) in a tank with a bright substrate, such as silver sand, their colours will wash out completely, as the fishes try to "blend in" and avoid predators. Keep the exact same fish in tank with a dark substrate, such as black gravel, and the kribs will develop show more intense colours because they are less afraid of being seen.
Another aspect is that fish react to substrates in different ways. Fish that like to dig, like
Corydoras, dwarf cichlids, and even plecs, will enjoy a sandy substrate much more than gravel. It's also fun to watch them dig. Some fish absolutely
must be kept with a sandy not gravel substrate: flatfish, violet gobies, and spiny eels for example. Midwater fish like angelfish couldn't care less about the substrate, so you have more freedom there. Coarse gravel is easy to clean, so works well in tanks where you want to siphon out waste easily, as might be the case in tanks with messy cichlids or pufferfish.
So while yes, you're free to pick and choose a substrate by whatever aesthetics appeal to you, any choices you make should be moderated by the demands of the fish you intend to keep.
One last thing: the two plants by the big rock are going to die. They're both
Dracaena sp., and while (sadly) commonly sold as aquarium plants will gradually rot and will be dead within a few weeks. Dig them up and stick them in a pot with some compost, and water sparingly. Otherwise you'll get the pleasure of watching your hard-earned cash slowly rot away.
Cheers,
Neale
Yes couldn't agree more about the fish blending in to their surroundings, it is more complex than people think. Trying to create an ideal habitat for all these fish in the tank is near impossible, satisfying every need and requirement would be hard especially if the tank has quite a few varieties of fish. Although I think making the surroundings as comfortable as possible, taking time to research the species and finding out which substrate/water condition/food etc is best for certain fish are some of the vital things to keep in mind.
The colour of my gravel isnt a great problem to me, as long as it doesnt cause my fish any distress and they are happy in their surroundings then so am I. If it did cause a problem i'd be the first to change it.
As I am new to fish keeping I am going to be opting for relatively straight forward fish to keep. Angels or Discus amongst a few more will be satisfactory. I know Discus require a lesser PH but thats not a problem as my PH is fine and I am keeping a close watch on my water condition and doing as much research as possible.
I was considering sand quite seriously, although I heard it can be a harder to clean than gravel and can sometimes clog filters, but then again i've never used it as a substrate so I cant say from experience.
You are very right about the plants. The red tinted is dying already, the leaves are closing up and its not looking exactly healthy, the green one is fine for the moment, but i'm going to keep an eye on them.
Cheers for the heads up, much appreciated.
Here is my new fish tank, still not finished more plants to be coming soon.
