"Pszemol" wrote in message
...

Are they walking on the substrate or swimming like plankton ?

The ones I can see are swimming. I doubt I`d be able to see any crawling on
the sand and rock (Its been a long time since my eyesight was 20/20).
I was thinking: On ipsf.com I read about a "Pod-Mat" of Ulva
Macroalagae. This is part of a breeder kit for a refugium or separate tank.
What if I punched a few small holes in a seashell and put the mat in there?
I`d put the shell open-side down.
The Pod-Breeder would be hidden, but still inside the main tank. Would that
produce enough pods to feed the Mandarin?