I'm getting to the point where I'm almost ready to just pull everything out and switch to a full hardscape, as I am at a complete loss as to what I should/could do to remedy my situation. Here is the background, and what I have tried:
Here is what the tank used to be:
Lush and beautiful. It was so easy too. In the beginning all I really gave it was light and weekly flourish doses. It thrived for over a year.
Then algae started to cover everything, and kill off my plants. I tried everything. Shortened photo periods, increased water changes, 4 ay blackout, increased Excel usage.
I changed the bulbs, then just under a year later I changed them again. I tried just using one of the two bulbs. I was told it might be a nutrient deficiency in the soil (though that doesn't explain why duckweed simply melts away if I add any to the surface), so I added root tabs. I bought a new filter.
With everything I have thrown at this the slow and steady decline marches onward.
Despite some clearly poor plant health, the fish and shrimp seem to be fine. I have the same amano shrimp I got over two years ago, and I have heard they are very sensitive to water quality.
I have a hard time interpreting api test strips, but as far as I can tell it's 0 NO3, NO2, 7-7.5 ph, KH 120, GH 120
If anyone might have any tips, or experience with anything similar, I would greatly appreciate some input.
Here are some pics of the tank, a week since the last water change and glass scrubbing: