Yellow Labs - Behavior Question

I have been raising red zebra's with success for years now, recently started
Yellow Lab 29g tank. I ordered them online so was not able pick sexes. Ended
up with 3 males and 3 females. Very unactive fish. They all seem to sit in
nitches under the rocky boulder-like landscape, occasionally changing
positions. Sometimes just sit next to each other. No aggression yet, is this
normal behavior for Labs? Temp 82, PH 8.2, Salinity 1.008? I know I have the
wrong food, have normal OSI Chichlid flakes, will be introducing Spirulina
Flakes exclusivly this afternoon for a couple weeks. Fish were added 1 week
ago, is this inactivity their norm, or do I have a setting wrong?