manual

Just picked up this drop in manual fleece roller for my IM 40L AIO. Really happy with the placement next to the protein skimmer but I have a question. What do I put in the open space at the base of the plastic towards the cone end (pictured). It looks like a place for additional filter media...

I know that this site has literally ALL of the answers and I’m very thankful that I have you guys to ask questions. But, if you had to pick a book, or books, that a newbie like me should have, what would it/they be?

I have 3 AI Vega Colors’ over my 75 mixed reef. These lights are almost 8yrs old but still doing the job. (They’ve been in storage for half of their life) I’ve been using “easy mode” for light setups/ramps but I’m looking to play with the “manual timer setup” to have more control of when whites...