40lbs crushed size 0 and 1 argonite, plus 100lbs southdown/old castle sugar grade sand.
Agree with the earlier post about removing any filter floss. If you wish to keep it in there, thats probably ok, but I'd be rinsing it frequently.
Also not a bad idea to check your incoming water (before and after mixing) for N03... even if you are using RO
, or buying it from somewhere you never really know whats going into the tank unless you check it.
I've heard of many people getting NNR
without a bed as deep as mine, I think 2" is enough, and even know some folks here locally who export nitrates with LR
only, though you do need quite a bit of it.
Another thing that helps is the type of inverts in the tank. Xenia can actually export some N03 as well.