Oh, nevermind....
You can probably get by with some water changing, however skimming as you probably know, provides increased oxygenation to the tank, and my view is, any skimming is better than none. Non skimming tends to catch up over time...........IME anyway.
The skimming principle is nutrient export. This can be accomplished (apparently) with macroalgae (regularily pruned and removed) as well.
The amount of bioload, of course, seriously contributes to the need for skimming.
Watch the O2 and nitrates if you don't skim.