If I'm gone for a short period of time, the Greenwater Technique really seems to help...i.e. if we head out this weekend to scout weeding locations I'll just double up on the phytoplankton tomorrow morning (add 2L of FRESH phyto instead of one) and no worries about the baby clowns. For my GBG's, they're getting a LARGE water change tonight and will probably just get their first "fast"...getting fed Saturday morning and Sunday Night..there's enough pods in there to tide them over (but with my cultures I could always add MORE for the lean times while I'm gone).
The one big thing is that for the most part, LIVE feeds and LIVE phyto don't "spoil" and ruin water quality...thus you can stretch your feeding time out (i.e. I technically haven't put ANYTHING in with the baby clownfish today...)
Matt