personally I would say clean the sand out of it entirely and just have a BB fuge with a huge hunk of macro
if you are using it for nutrient export this is the best way to go. you can then in a few seconds witha shop vac every now and then vacuum out what settles for permanent and absolute removal
if you are using it to grow pods to support something sepcifically.......use a BB as well and just make some pod condos with rock rubble. Again, you can at least remove excess detritous from the floor instead of letting it rot in a sandbed just so organics can be released all the time