I have 4 tanks. Started with a 20 gallon, then added a 10 gallon when my Bolivian Rams had kids. A year later got a 30 gallon from my sister. When my fish outgrew that I got a 55. So, the 10 and 20 are now fry growout tanks.
The first pic is how I set up the 20 gallon my son gave me. I had told him I wanted a natural tank because when they were little I had to have all the color, pinks and purples for my daughter, greens and blues with skulls for my son. He gave me his old 20 gallon setup. I was completely suprised too! Didn't even know he had one. I have no clue why I got rainbow gravel and fake plants! I turned it into a tank that looked like a mix of my kids' tanks when they were little Yuck! Took about 1 week for me to replace gravel, plants, everything! 2nd pic is the same tank redone about 2 weeks later.
Third pic is 2 years and a ton of research later, most of the stuff moved to a 30 gallon. Added driftwood and CO2. Much better!!
First setup What was I thinking???
Better, but not quite what I envisioned:
Final Setup of my planted tank. Still want one more big driftwood piece for the right side to look like roots coming down from above. Totally what I had always envisioned! Rams agree too, spawned the day after I changed it over!
The African Mbuna tank. Started with a 30 gallon and the fish were all small at 2" or so. Used small river rocks while they still fit in the caves it made. They soon outgrew the 30 gallon and I had to re-home some. But even the ones left were too big at over 4" so got a 55. Now they have all the room they need. Switched over to lava rock because it makes bridges and bigger tunnels. Lot more fish too.
1st setup, used anything I had that would make caves:
2nd setup after putting in small river rocks and changing to a dark blue background. Fish still in the 2-3" range:
About 6 months later: Put more lava rock, fish are seriously outgrowing the 30 gallon! They were between 3 and 5" here. Looks like the tank shrank, huh?
Final setup. Fish are now in a 55 gallon. Most all are over 5" now with some smaller 2-3" fish growing out. They now have enough room to swim as much and fast as they want! Lava rock caves, some big river stones under those Also some black PVC pipes as small caves under all the rocks.