Hi, I got some frogbit from an ebay seller and it arrived Monday. It looked fine, it's been hot in my area so I was worried and one leaf melted, but overall they looked good. Today I looked at it and there are tiny black balls attached to the roots. I'm doing a fishless cycle on my tank and I'm at .5ppm of ammonia as of 5 minutes ago. I started dosing at 5ppm (I want to add all the fish at the beginning if I can) on July 18, and this is just now the first time it's on its way to 0. Originally I went to the LFS (which was really crappy!) and on his advice, I got hornwort and anacharis which made the ammonia drop to 4ppm but the hornwort was AWFUL! My tank is full of awful debris now, but I can vacuum it up when I do the water change, but I just mentioned that in case these plants or the debris might be the cause.. I threw out both of them because of the shedding and the anacharis looked ugly. I also got a ramshorn snail on those plants and I had to send it to its final resting place even though I thought it was cute but I knew they could reproduce asexually and a tank I had as a kid (which was probably not taken care of properly, I'm sure) got overrun with snails. That was probably two weeks ago at this point and I haven't seen any snails since. The one picture I did find resembling my black dots everyone replied saying it was snails! So then the ammonia stayed the same, and on Monday and I added the frogbit and some marimo moss balls. I just noticed a big change in the ammonia yesterday, from about 3ppm to 1ppm and today .5ppm. But also, today I noticed black spots on the frogbit roots. They arent on the leaves or moss balls or other non-plant decor, and I looked up all kinds of things, what freshwater algae might look like, black spots on frogbit roots, black spot on aquarium plants, black balls, etc and they don't come up with anything that looks like this. My light is a Beamswork 30" EA 80 36x - 1750 lumen 30x 6500K, 6x Actinic.. I'm having a hard time understanding lighting requirements and what is considered high/medium/low light.. is it the 6500k I go by? Is that medium or low? I keep the light on basically all day because my room is dark and it looks so pretty with the light on, even without my fish yet. So here's a picture, the thing in the upper corner is a straw that I have corralling my HOB filter so the plants don't go in front of the waterfall and get pushed underwater constantly like they were at first. I use excel flourish and have been using it every other day. The tank is a 20g L and the PH is around 7.6. Hopefully that's enough information for someone to be able to tell the cause. I also have driftwood soaking that I'm going to add java fern and anubias nana to.. as long as things are okay here. Thanks for your help or even just taking the time to read this!