You should do it! Mangroves are awesome. I love them, and it's always fun when a random guest is like... wait a minute is that a plant in there??
It's doing... OK. Not the fastest growth, maybe one set of leaves every 6-9 months? Things I attribute the slow growth to, in decreasing priority.
1) It's basically an epiphyte right now - I have it semi-anchored to a rock, and then wedged behind my return locline. Roots would definitely prefer to be in a substrate / muddy, not growing as a hydroponic lithophyte I think.
2) low nutrients - max I've ever measured is NO3 = 10, PO4 = 0.06. There's just so much macro and softies they suck up the water column nutrients (see #1)
3) lighting is too close - so it gets plenty of light intensity, but I think if it got more of a 'spread' of light on it including the stem it might be happier.
I have plans to fix #3 in a month or two once my indoor plants get to go back outside, and hope #1 will fix itself in time once roots make it all the way down the rock into the sand.
Other random commentary - avoid root disturbance, definitely don't break roots to let salt in but even moving them seems to slow root growth for a bit.
