@gbroadbridge,
@FishOkay
Yes I am aware they all do different things but trying to get insight from people who use the various methods. A skimmer removing nutrients is same as an ats except i feel ats more effective, good mechanical filtration will also help with nutrient control. Skimmer can help gas exchange which an ats will only help when lit. I have heard some people get no skimate from skimmer after using roller filter if true then other than aeration it will serve no purpose.
So do you have a roller filter? If so what brand, size and tank size with sand? And how long does roll last. The on going cost would be high if you get one or two weeks per roll but 3 or 4 months not so bad with the convenience.