Siporax vs matrix, what's the difference?

[bubbaque]

In my tank upgrade I am wanting to go a minimalist Aqua scape and was going to use siporax or matrix in the sump to help replace the lack of LR. What's the difference and which is better?

 

[sa6hir]

I've got siporax in my set up but my friend as matrix both our nutrients readings are almost the same, saying that he's got about 20-30 fish where I only have 10. And both our systems are over 200gallons, im just have problems with phosphate at the moment!