pitt420dude said:
Is a flourite substrate necessary? If I get plenty of light, (but less than 2.5wpg) is a
CO2 system and special substrate necessary if i just want to have a few live plants in my 55
gal with uncoated gravel?
You can grow many plant species in a barebottom tank. Some heavily rooted plants will only grow well with a firm hold in a substrate material. There are many many choices of substrate materials you can be successful with, to name a few;
Sand, plain gravel, kitty litter, Fullers Earth, Turface, Potting soil, garden loam, and the commercial products Flourite, Onyx Sand, Eco-Complete, Flora Base, Aqua Soil, Power Sand, Volcanit, etc. and any of these can be combined together and with additives such as Laterite, peat, and mulm. I have a recipe I use for low light non
CO2 injected tanks.
IME it's low light tanks that benefit more and have fewer problems when using a "richer" substrate. "Richer" meaning higher amounts of iron and organic material. But I will stress that it's possible to have a successful planted tank using any substrate with any combination of lighting and
CO2. I'm just relaying that in my experiences the odds of success improve with a richer substrate in lower light conditions.