You can still do a lot with a smaller tank though, once it's not ovestocked with fish. Mine isn't the best by any means, but it's the same size as yours, and this is after a year of plant growth. No major lights/CO2 or anything like that, just a cheap amazon light, some root tabs, and some trimming now and then.
Last October, tank was about four months old. Most, but not all, of the plants came from the amazon place I linked earlier.
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Last week;
View attachment 111766And I only started keeping a tank a year ago myself. Just kept adding more plants, fertiliser now and then (and I often forget that!), moving the plants around when I found out I had huge plants at the front and small ones at the back, and mucking about with different driftwood and things.