With no more ammonia going into the tank, and some fast growing plant's like water sprite, anacharis, and maybe some slower growing plant's like crypt's ,anubia (attached to the wood), and then performing a large water change ,you could add two or three small leopard danios,glowlight tetra's,or bloodfin tetra's.
Feed the fish sparingly once a day, or every other day, and watch for ammonia and or nitrite's. If they rise above .25 then change out a couple three gallon's of water using dechlorinator for new water added.
In my view,,with lot's of plant's you could add said fish without seeing ammonia level's rise to dangerous level's .
Add too many fish,too large of fish,, overfeed the fish,,and all bet's are off .