I've tried going cheapo and growing them in a low-tech (just water and soil and a single betta, no filter whatsoever) tank by my window. Doesn't seem to grow at all. Not dying, but not growing either. Maybe they will need a longer (way longer) time to have runners.
Growing them now in 2 ft tank with cheapo aquarium lights and cheapo filter, again no growth, not dying either.
They grow well and thick under T5, CO2 with good water circulation. Hope this answers your question.
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