Runtz guerilla grow

It's an inch btw not a cm. Soil can be tricky. Ppl mainly over water or water too often, (is another form of overwatering), with a cup that size it really only needs 50-100ml of water every 3 days and as the plant gets bigger and u uppot the plant will need more. But it stays the same every 2-3 days. My plants now take 1l of either nute mix once a week with 1-2 water feeds inbetween, you'll know without even having to touch the soil in a couple of weeks. You'll see the top all prickle, that's your roots searching around for water, don't panic when you see this it just means your water ings are on point and you have healthy roots. 1inch down if you hit hard earth it's still watered enough if only slightly damp at that level then feed. Feel free to DM me if you need more detailed info for feeds and so on. Good luck happy growing.

Yes, rotting from being too wet, too long. Water only when the top 1cm is dry before watering again and she should recover...... hopefully. She will need transplanting soon, so once she has recovered and making good new growth, this will be an ideal time to do so. Once in the new pot, it is best to water deeply to run off every few days and not watering again until the top 2-3cm (note the change) of the soil has dried out. This could mean only watering every 2-7 days, depending on temps, the plants requirements and the water holding capacity of your soil mix. Hope this helps, Organoman.

With limited information it looks like she is overwatered. In soil you have to cycle a wet and dry time. Or add lots more perlite or coco to mix. Roots are not getting enough air.