Ok, my tank is set up with 2 oscars and 2 catfish....forgot what kind of catfish. 1 albino and 1 tiger oscar and the catfish are black in color. I have black rocks at the moment but I REALLY wanted to start with sand. I love the way the black looks, but think it would look better with a light color sand. What are your thoughts on rocks vs sand....not so much the color question.

I am a little confused, are you saying that you only have rocks as substrate, no gravel or sand? If so, I think this is a very bad idea. You need some kind of substrate is whether it be gravel or sand. Fish could damage itself very easily if you only have rocks. Personally, I prefer sand over gravel. There are pros and cons about using both these substrates. When you use sand, all the crap settles on top and doesn't go underneath. This is a big advantage because the filters remove it a lot easier. With gravel, a lot of that there tends to make its way underneath. So the only way of getting it out is to gravel vac thoroughly.

The problem i have found with sand is that when fish move it around it can cover fish waste and then you cant get rid of it. With gravel, a gravel cleaning will clean this. Generally tho most waste just sits on the top and you just syphon it off

As ofl says the problem with gravel is that you have to gravel vac

I personally use gravel for oscars, sand for my discus

I have never had a problem with the sand covering anything up. There is enough space underneath it for things to work their way under. Cleaning gravel is a lot more time-consuming as you've got to put the gravel vac into all areas of the gravel, okay if it's a small tank, not really if it's a very big tank. Also, try and keep the substrate about an inch and a half feet. Again, if you're using sand, you can go a little bit deeper than this.

I have never had a problem with gravel cleaning and my biggest tank is 6ft x 2.5ft x 2ft deep. I just remove the rocks and gravel and clean it while doing a water change. I do half a tank every 3 weeks and it takes about a third of the time it takes to drain out 50% of the water. You have to move any decorations with sand too as lots of waste tends to gather under them