Yes they are...and in a nano, the DSB
is so finite that the populations never reach adequate size to maintain the tank. I had this discussion with Bang...short version is that a nano DSB
isnt big enough to filter the tank. Due to the fact that the infauna will not reach adequate size to keep it from suffering from "lump syndrome," Nano's are the only tanks that I would ever suggest putting a sifter in.
Here is why. Sand lumps because the bacteria excretes a sugery coating that binds the sand together. This means that water doesnt flow through it and it will develop pockets of sulfides. If one of the pockets are disturbed, it will wipe out the tank. There are only three ways to keep this from happening. 1. Keep a shallow sand bed instead of a DSb
. 2. Adequate infauna to move the sand around and keep it from binding together. 3. Sand Sifters.
The problem is that sand sifters will not only depleat the worms and pods
in your sand, but eventually your rock will not have the pod population either. The worms in the rock will be fine, but the pods
will be basically non exsistant.
I say all that to say...I would put the watchman in the tank.