Adding sand to old tank

[TheOldMan]

I have a established 40 gallon Hex tank that I just restocked with a few Curviceps. The tank is well planted and would just like to add about an inch of sand to it as it has a medium sized gravel base. Is this advisable to do and what kind of sand should I use? Would this be better if I want the Curviceps to breed? The tank has some driftwood caves and may add a bit of rockwork for them too. These are my first cichlid in about 45 years. I have bred Angels and Jack Dempsey's a long time ago.

[Mzungu]

I am not too familiar with how those guys spawn, so I'm not sure if having sand at the bottom would help or not. However, I do know that over time (be it a matter of months or years) the sand will eventually settle below the gravel. So a top layer of sand won't last forever, especially with cichlids, water changes, gravity, and plants. :)

I don't see how sand could hurt the plants, but if they're doing well without it, then I wouldn't worry about them.

Are you concerned about the sand for the fish's sake, the plant's sake, or aesthetics' sake?

[TheOldMan]

For the fish's sake to breed. According to a review of them in TFH: "Typical substate spawing placing eggs on a horizontal leaf or flat stone."