Sorry to hear your plants aren't doing well.
So what do you mean by "gunk"? Is it algae or rotting plants?
If you haven't added any fertilizers yet I would guess that's your problem. My plants are doing much better after a meltdown last October, by adding Leaf Zone which provides I and K, and CO2 Booster as directed. The rest of the micros are provided by the fish food, as suggested by Diana here on the forum. Easy, no fuss, and not that expensive for a 20H. I assumed the fish waste would fertilize the tank, I was wrong.
Remove all rotting vegetation, it will lead to more problems. I know you don't like Corys, but I'm a firm believer in bottom dwellers to stir things up down there. I love my Peppered Corys, they don't swim around frantically and don't bump into things. They just calmly poke around on the plants and bottom looking for food, I don't know what was up with your albinos. Maybe they can't see very well.
I always wondered if your light was bright enough, but your pictures are similar in brightness to mine, so I'd try fertilizers first.
I also added a cheap HOB 10g filter for the other side of the tank from the 20g one a while back, I didn't feel I had enough water circulation, and gave me peace of mind for my bacteria colonies. I alternate changing the filter pads so I always have a colony to take care of the ammonia and nitrites.
Our paths have been similar so far, I hope what I learned helps.
The gunk is poo, un-eaten food (I think?) and... well, it just looks like brown fluff. I'm not entirely sure WHAT it is, to be honest. It's everywhere. The substrate, the plants, the driftwood....
I am dosing (very infrequently) with Excel Comprehensive. I had a member on another forum talk me into this: http://www.aquaticplantcentral.com/f...e-pps-pro.html
I'm not sold on it simply because it's way more complex than I ever wanted to get in to. I don't doubt that it works, but it's just way more effort than I wanted to put into this hobby.
I have root tabs in, but other than that, I don't do much. My plants have never thrived and I'd say about half of the plants I've purchased have died. I've lost well over $100 in plants. Some nice, stuff too.
They either die or just don't thrive.
I would be willing to try cories again (esp since my stock is reduced from fish deaths), but I don't know how much food even reaches the bottom... The remaining fish pretty much gobble it all up at the surface. One of my peacock gudgeons died the other day (she was really really thin) and I wonder if it's from her not getting enough food. They are bottom dwellers and never really come to the surface, even at feeding time.
Thanks so much for your input! I really appreciate it.