Correct pond matrix is simply larger. Identical material and production method. Large pieces should facilitate more anaerobic denitrification provided the flow through is gentle enough. Kudos for actually looking into stuff beyond a single set of recommendations, even if it is my own recommendation you agree withThank you both for the very useful info. I did some more research on both of your suggestions, and the matrix did stick out to me as the best option. I was wondering about the pond matrix as it was listed as being larger, so I am leaning towards that. I was a bit skeptical because I thought it was for "ponds", but it looks to be the same as the smaller matrix media, just larger? I agree that doing your research goes a long way, and saves you headaches down the road..
Just put in my order for 4L for my 150g..good idea to make some kind of wall, I may consider something like this.I have 8L of matrix in my 200g tank. I made a "brick wall" out of it by putting it in different media bags and stacking them in the sump. This way the ones on top get higher flow and the ones on bottom get lower flow.
I used some different media bags as well. Some were pretty "open" and had larger holes, I put those on top. I got some smaller ones that were tightly knit and put those on the bottom.Just put in my order for 4L for my 150g..good idea to make some kind of wall, I may consider something like this.