The other plant I think that you are asking about is Hygrophila sp. "Brown." This hybrid can grow very quickly in a high-tech set up, and like grandulosa it is a bit brittle, so planting needs to be done in the same vein...with a little caution.
It does tend to creep, preferring to throw down aerial roots and spread that way. It will form side shoots quickly. The plant never tends to gain much in height, though, unless you trim the aerial roots, and even then it still tends to "leaning" at best. Interesting plant, for sure!
My understanding is that this plant grows alright in low-tech setups as well.
The H. "Brown" is similar to H polysperma. It has serious weed potential.
I've had well over 1" of growth per day.
I would like to see more pics of H. "Brown". It seriously looks good in your pics. Orangish red. It looks similar to bold (greenish brown) and seems to grow just as quick. I would actually love to have that plant while evryone else fights over the other :p. Im just not digging the weed part. I already have enough weed plants I got rid off recently.
Would like to see more pics as it gets better red colours.