My plants form emmersed leaves, while submersed...

If you let it hit the surface for more than a day or two, they can sometimes form the ugly emergent leaf morphology.

I've seen it when they did not do that every so often also. They might get confused???
L gigantea also, but it's a rare, temporary thing. It should revert back.
A few plants do this.

It's a fast growing weed that is banned in the USA. That does not mean many hobbyists did not have a grow it a few years ago. I found some in Florida once and killed it. Look like someone who kept ponds tossed a bunch of out in a single spot.

Since it can get a full 35cm across, and can grow 5-20cm a week, it's not that suited, however is a pretty and dramatic plant submersed. Few keep it here and then only a few pond keepers down south in the USA last heard.

But regular water Hyacinth is legal
More market I guess for that and it's too late to solve anything from banning it.
the same could be said for Hydrilla, but they still banned that one


Not really consistent are they?

The plant will use a lot of nutrients, particulalry NO3.

Regards,
Tom Barr