Plant Problem?

Can anyone tell me if this is a problem for the plant?

Discoloration seems to be on the bottom leaves only and I'm not sure why. Could it be lack of light, lack of nutrients or something else! Otherwise they seem quite healthy.

need more info... soil, temps, watering, lights, pH... etc..... help us, help you.

temperature is at a steady 72 Farenheit...soil is miracle gro moisture control...using two 23 W CFL bulbs...watering at least every other day.... i don't know the PH

Kinda looks like a calcium deficiency

It's the MG.....DO NOT FLUSH! That will only increase the problem. Do not over water. Try and let that MG dry out to ALMOST wilting the plant (Don't keep it moist) before waterings. Ignore the pH, your in soil,,,well kind of.
The more damp that soil stays the more it will release the "timed release" balls of doom,,,,,er, eh "nutrient".

Down the road,,,avoid any MG product. They will work,,,,but the work and attention to make it work, are not worth the results.