The tank is JBJ Nano-cube 12DX, 12Gal, ~14"x14"x14". Light is 48W ( 2X24W 4400K CF ) . Filter is integrated, it's 3 compartments in the back and powerhead.
Fish - 2 otos, 2 SAEs, 5 cuhli loaches. Some snails - pond and MTS.
Fertilization PPS Pro plus pond tablets in the gravel. CO2 20ppm, 1bps injected into the powerhead. Water change 50% once in a week or two, depending on how much water my houseplants need

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As far as ludwigia. This tank doesn't have a bulb on a background, so whatever grows there tends to bend forward. One day I cut a stem top and the plant started branching from every leaf node and bending even more. That's how I get this look.