I have refugium in my Waterbox 50.3 AIO in one of the chambers. I purchased media basket that fit the chamber from three sides and left some spacehttps://www.tunze.com/en/details/8831.000-led-eco-chic-refugium.html from the fourth side, just enough for Tunze Eco Chic Refugium Light. The light is waterproof, so no need to cut the film on the back of the tank. Chaeto grows like crazy!