Sump-DSB vs rubble vs rock

[Shilpan]

Hello
Got a 400L tank. And I think about 100L sump. Maybe 80L.

Finally putting rockwork into my new tank, just finished acid bath and soaking and scrubbing.

Anyway, there's a section of the sump for a refugium which is about 1/3 of the display tank surface area. What's better to put there? A DSB? Rubble? Or a large piece of live rock?

Macroalgae is a bit hard to come buy in NZ, I might get some later but that'll be a few months down the line. Just wondering which of the above is best? Problems with DSB?

 

[lmforbis]

I have rubble. I figure that gives a place for the pods to crawl around. I have a Mandarin so a healthy pod population is essential. I have on occasion had large rocks in there but more to keep them live until I know what I want to do with them. I've never tried a deep sand bed. There is a product called marine pure that is an artificial rock, comes in bricks or balls. I have read that the blocks are really good to put in the sump. They provide a very good environment for anaerobic bacteria. I have some of the balls but I keep them in my sump and pull a couple to help in my QT tanks. The large blocks are supposed to be best for denitrification. You might look into them.

 

[Shilpan]

Cheers thank you!