I set this tank up about a month or 2 ago and when I added the anubius it was perfect and green! I have been getting new growth and it’s been looking good until the last few weeks when I noticed brown on some of the edges! I have uns controsoil and recently started to dose Niloc g thrive once a week! I add about 1.5 ml for this 9 gallon fluval flex! I didn’t notice the brown edges till after I started fertilizing! Also the filter keeps pumping out the brown mulm that collects on the sand and anubius even though I clean the tank once a week and clean the filter! Does anyone have a idea as to why the brown edges of the leaves are happening cause the anubius looked great a couple weeks ago! I did have spider wood in the tank originally but had to take it out cause it was messing up my bettas fins! Thanks for any help!