No just put a small handfull into a container and pour a little vinegar, it should fizz immediately - good sand. No fizz = potentially bad sand.
The skimmer is not needed if you are strict with frequent water changes, you can add that in a few months or so. It removes organic waste from the water so you have less nitrates. Power filters simply trap waste and if not changed enough, does more harm then good (high nitrates, other bad bacteria). You can run a hob
filter along with rock, like lando says it's not needed but you can use it along with lr
. I use a hob
emporer 400 for media like carbon and filter floss. You may also be able to buy coral rock cheap at a store (dry base rock) and seed it with just a few kgs lr
. The system does not have to be too elaborate for 2 percula clowns, imo