Substrate Question

[The Duke]

Hi ppl. I am about to change my gravel substrate over to black caribsea sand. I am planning a heavily planted tank and have toyed with the idea of using a planting substrate. If I did so wouldn't it just get mixed up with the sand over time, the sand eventually working its way to the bottom? Also, how long does a planting substrate last? Surely the nutrients would run out at some point? Any pointers?

 

[DrRob]

Generally they're designed to be used on their own. You can get sub layer stuff. They do look nice though.

It does lose its oomph eventually, but it also has a good holding capacity and will take on nutrients from the water.