Help/advice needed

[hillegom]

Good advice with the sand. Thats what I would do. Cheapest. There will be some nutrients left, but you could deal with that when you cycle for 30 days.
As well, I would clean the rocks. either pressure wash or soak in acid. I can't remember what kind, but someone will chime in here. The dried algae will put a lot of unwanted nutrients into the water column.
You could cycle the rock in a couple of 5 gal buckets and a power head.
Good luck with it and glad to see you are coming back into reefing