What would be the best substrate for a planted 120 with 25 cory's?
Eco-complete is loaded with close to zero nutrients... It has the ability to absorb nutrients from the water column and retain them for plant roots.If you want easy, go with eco-complete. It's loaded with nutrients and is better than gravel or epoxy. It's easier than making mineralized soil, but it's gonna be expensive for a 120 You sound like you may want to really research what type of plants you want to get. Plan your tank setup around what plants will be in there. Corys are hardy little fish that can handle a wide range of conditions.
+1 on thisEco-complete is loaded with close to zero nutrients... It has the ability to absorb nutrients from the water column and retain them for plant roots.
MTS capped with Eco-complete is a good choice if you want a cheap solution to a nutrient rich substrate such as Aquasoil.
Im sorry, may they rest in peaceI used the Black Diamond blasting sand in my 60 gallon planted that I have pics of in my profile. Never again. Too sharp like glass. The VERY VERY heavily planted 150 gallon I just set up has MGOPM, Walmart Kitty liter, Pool filter sand and capped with very small natural tan/white/brown gravel. Love this and my corys are in heaven.