Can you add a sump without drilling the tank?

[seado]

I have 120 gallon tank with DAS H-99 skimmer, it is the one that is built into an overflow box in the tank. There is a pump, carbon pad and a foam filter. I assume I should remove the foam pad? My water parameters are perfect, 0 ammonia, nitrite and nitrate. I had asked previously about adding a refugium and got suggestions for a hang-on and in tank version. I have yet to do anything. I wondered if there would be any advantage in my situation to adding a sump and how I would do that? I am not plumbing-wise so need lay persons instructions. I do not want to tear down my tank so drilling is not an option. any help would be appreciated!

[tendar]

If your perameters are good I dont see the need for a sump, but if you want one you can get a hang on over flow box to run to a sump and then have to make a return or 2 that hangs on the back but it will requires some good plumbing. I am assuming this is a acrilic tank. If it is the hang on and returns will be tough with out drilling.