would under watering cause a plant's leaves starting to turn brown . but it is only the bottom leaves the top leaves are fine ps i now this sounds like a dumb question but please answer it because im trying to figure out the problem
You need to provide more information and pictures if possible so people can help you. The general answer to your question is no, underwatering is probably not causing the problem you are describing. You would notice the entire plant getting droopy if it was not getting enough water. Are you in budding phase, like 3-4 weeks in? The older fan leaves naturally start turning yellow and then brown as the plant uses their energy to make buds. If not, then what kind of soil, what kind of lights, what fertilizers are you giving, how often do you water, do you check your pH, and what is it if so? A pic of the plant would really help in figuring out what is wrong, if anything. You should also remove your duplicate post of this question.
could it be from the heat and underwatering ? also i have miracle grow potting mix. and the plant is still in veg.
Can you take a better picture? Not trying to be a dick, but that one is too out of focus to tell anything. Also, can you take a picture of the plant as a whole, it will help in determining what is wrong with it. If you were underwatering, all the leaves on the plant would be droopy and "sad" looking, so if you don't see that, underwatering isn't the problem. Heat might be a problem, how hot does it get in your grow space at the hottest? What kind of lights are you using (fluorescent, Metal Halide, High Pressure Sodium) and how close to the plants are they? Miracle Grow soils somtimes have time-release fertilizers in them, if yours does you will want to transplant out of that dirt into a better potting soil. Look on the bag to see if it has time-release ferts in it.
