I have a 50 gallon, the substrate is organic dirt capped with sand. I used a mix of some play sand and pool filter sand, so i did have an issue with the type algae that feeds off of silicate from having used the play sand, and tannins for a while. These are the two plants that seem to show this issue the most, but I'm pretty sure they all have it. Some of the hygro leaved also have pin holes. I dose flourish excel, flourish, potassium and iron. These are what my LFS sells. My nitrates are bellow 20, gh is at or over 300, kh is at or over 300 and ph is at or over 8.4. I keep the temp at 78. Our local water sources have a lot of limestone and granite in them, so that's why our water is so hard. I do 50% water changes every 3 weeks. I thought calcium. I make my own root tabs after following some tips from, I think, an Aquapros video.