Last year at this time I was planning to tear down my 29 gal and replace it with a 33 gal long. Now it's time to tear down my 15 gal and replace it with a 20 gal long. I'd like to do a sand substrate this time - any suggestions on what type people prefer? Any pros / cons to light colored vs dark colored? (I've always used the typical aquarium gravel in the past). My current stocking plan is 8x kuhlI loaches, 8x furcata rainbows, and my male borellI apisto. Does this stocking sound ok?