i havent been using any fertilizer.they do get their nutrients from fish waster and minerals in the water.i also have some chemicals that i got from a guy when i bought a bunch of stuff.its something to do with plants.but im not sure what its for..3 bottles
1.strontium chloride
2.blended calcium salts
3.sodium hydroxide
i think the guy had stuff for a saltwater aquarium and i think thats what it goe too.but im not sure if its for plants or for corals and things like that.to which i did get a small coral from him.i did a little research and couldnt find any info onto what those products are for.