Good point about the uneven spread
@purpleinopp!
Thanks
@WillC, then I think I will remove some soil from the top. I don't remember exactly which potting soil I bought for this plant, but I normally buy a pre-packaged indoor plant potting soil for most of my houseplants. According to the (google translated) website, it has "garden peat, coarse peat chunks, peat litter and TerraCottem [... and] sufficient nutrition for approximately 180 days". I don't think all my plants discolor the water but I've seen it happen a lot.
