Got a 55 G that I am updating, My problem lies with the sand. I dont know what to do with it. how do I add it? before or after water?

After I do believe not completely positive though. You just have to wait for it to settle to the bottom make sure not to have a filter running at the time though.

It usually depends on the type of sand you have. It u just have any old normal sand, try rinsing it out before putting into the tank. If you just have live sand no need to wash but just add. I would say there would need to be water in the tank before adding sands to it.

If it is aquarium sand(not live) then I like to soak or rinse the sand in what ever water your using for your tank before I add it. If you add the sand first try and make sure not the disturb the sand too much, or you could fill the tank up with water and add the sand after. It is your choice but which ever method you use you will want to wait awhile for the sand to settle before turning on the equipment.