Hello! I'm still rather new to plantkeeping and have had luck keeping my multiple Pothos and Philodendron alive at least, but it seems like any time I try to branch out to different plants something goes wrong 😓 I had gotten a Coleus around a month ago and it's slowly been losing its color and leaves. The soil is still moist so it's not under watered, but the leaves that are dying are turning black and crunchy. I haven't used any fertilizer on any of my plants, and I bottom water them with tap water treated with fish tank conditioner (I read it's helpful for nutrients). Any suggestions on what I should do to save it?

