Okay, first of all, its difficult IME... Attempt one, which failed... bought from aquarium center, planted in Flourite, daily trace dosing with a Flourish Root tab under it... did great for two months, went transparent and died after that...gnome said:I'm considering trying Blyxa japonica again, but I should probably figure out why my first attempt ended in utter failure. I bought some pieces where a few of them had little plantlets attached at the crown. None of the plants had roots but the leaves looked very healthy. Because they didn't have roots, they wouldn't stay put (in Eco-Complete) and every morning I'd find them floating around at the surface. They were getting weaker and soon the snails and shrimp were eating them. After a while, there was simply nothing left of the Blyxa.
Second attempt, which is working great so far, Eco-Complete with Ferti-plant under it plus a little peat, _deep substrate 3.5"_... very bright lighting, 2x36W PCF on a 15 gallon.. I think its iron availability with this one... root tabs plus a deep substrate with some organic matter to make more iron available to roots, also dose daily and dose a lot (10ml TMG, 10ml Flourish iron per week dosed daily, about it up it some more). You can easily grow the root outs, grab the crown with tweezers, plant very deep, then pull up on it until only 1/2"-1/4" of crown is buried. It will die long term if left like this but for a week or two it should be okay.. gradually pull up on it a little each week until the entire crown is exposed you should have a root system by this point. Did that make sense?
Every bunch I've had the old growth died off, I think its grown emersed...