i've heard through the grapevine that petco is having their $1/gallon sale again this week. i was going to pick up a tank to start my reef. im torn between a 20H, 20L, and a 29g. i currently have a 20L which i could use for a sump for a 20L or 29g or if i go with a 20H i would try to trade for another 20H for sump. i like the shape of the 20l, it gives a lot of options for rockscape, the 29g is the same footprint but higher, not sure if i like the cluttered look of a lot of rock to fill a 29g. what do you guys prefer?