If you have the money to throw into this, I would suggest looking at the HOB refugium just cause it will give you more water volume (stability), and you can add sand/mud, rock/marine pure, chemical and mechanical filtration. Here is the one I use
https://www.bulkreefsupply.com/smal...um-with-led-ligthing-system-cpr-aquatics.html. Now that comes with a light but I personally found it very lacking and not anywhere near the right spectrum so I went ahead and upgraded with this
https://www.bulkreefsupply.com/ecochic-waterproof-refugium-led-light-8831-00-tunze.html which fits perfectly and since I run at night gives a nice night light source in the room. I have live sand, 5 marine pure cubes, chaeto, filter floss around the intake, and a bag of BRS Rox Carbon in the output chamber (pods still escape into DT easily). Personally I think with the added volume of the water, being able to use mechanical, chemical and biological filtration along with nutrient export from the macro algae will do you better in the long run that modding the filter.
If you don't want to throw that kind of money into that, you could always get something like
https://www.bulkreefsupply.com/small-citr3-pro-in-tank-refugium-cpr-aquatics.html <-- that which is basically the same thing as the breeder box idea posted above with an extra pump to help "tumble" your macro, but I personally think you will have more benefits having the HOB refugium and running opposite light schedules than your tank for more stability.
EDIT: Great place to hide your heater as well, and does actually fit a nano skimmer up to the tunze comline DC 9004 if you wanted to use it as a pure sump rather than refugium.
