Hello! So I have had my tank up and running for a year and a half now and im finally deciding I want to dip my toes in the water of upgrading the equipment for my sump. For context I bought this tank used and the guy didnt give a ton of information on anything besides how to filter and such. I have already decided im getting new bio balls because he had a giant bag of those and what im assuming is crushed coral (??) mixed into it and it is by far the biggest pain to clean as it weighs a ton. With that being said I am going to attach a photo of what the setup looks like now (its dirty I know). All suggestions of things I should add / change are welcome. Also feel free to explain why I should add / or change said things thank you!