amphipods, or? 1 year newbie reefer anniversary wooo!

[sleepy.sunny]

are these amphipods? kind of worried. these things are EVERYWHERE on my rock & sand, i feel like theyre getting out of control, i only have 2 clownfish and CUC in the fluval 13.5 what could i do to keep them under control? I am upgrading to a 40 gallon in a week , will these little guys survive the transition ? thats if theyre not bad things.. thank you for the help!

p.s.
are green splotches on the wall coraline algae but green?

 

[Cthulukelele]

You'll see a decline after the move but they'll still be there. Your clowns must be eating good. Most tanks are filled with amphipods like these but they're only active at night cuz they're preyed upon by fish in the tank. You only see them all over the place out during the day like that usually in tanks that are very understocked/have fish/creatures that aren't interested in munching on pods.

They're harmless fish food 99 times out of 100.

 

[Shibaken3]

Could be copepods but most likely amphipods and they are good for ur tank.
Yes, coraline algae can also be green too.