Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Most of my tanks started with 'plain gravel'.
I had reverse under gravel filters running in a lot of them.
Where the UGF plates did not quite reach, on some of the odd shaped tanks, the plants grew really well.
At that time I had lots of fish in the tanks, so lots of fish food. I was doing water changes to keep the NO3 down, so this implies plenty of P, and most traces.
I was adding K, Fe (Leaf Zone) and Excel for carbon.
I gradually shifted over to fewer fish and finer substrate, but I still have several tanks with pool filter sand. This has reasonable water movement through the material, and does not hold nutrients (so is similar to fine gravel).