the algae is a mixture of
diatoms and others, it's beneficial but could be nuisance depending on tank type and parameters. Most blow it off the top of the sand for looks which is not a bad deal, the reality is plenty will live elsewhere.
As far as the pods, theres probably a ton and a ton of different species, if your super concerned about it you can siphon them through an airline hose (which doesnt work for larger amphipods) and plop them in a
sump fairly easy, if you transferred some
live rock and arent super concerned for any special reason dumping them is not a huge deal. Most of these guys breed like rabbits and will re-establish quite quickly in a well run system.
If you moved rock and other such items, many have transferred over anyhow so you should be okay there!