How big does carolina fanwort grow?

[Mcor]

I think I have Carolina fanwort. It could possibly be ambulia, wasn't labeled in the shop so I'm going on the plant profiles listed on this forum. Anyways, just wondering how big this plant grows and how to prune it? I only got it three weeks ago, in fact it was so small I bought three of them, and in these short weeks they've more than doubled in size. It won't be long until the longest stems reach the top of the tank. They were sold with a little ceramic ring at the base so they could be dropped straight in without anchoring or burying the roots. Any info/tips/opinions would be much appreciated!

 

[Sharpchick]

With the stem plants, when they get so tall they bend over on the water, or start loosing leaves on the bottoms of the stems because light can't penetrate all the way down, I pinch - right above a leaf node. Then plant the top, and usually the bottom part of the stem leafs out and keeps on going. I do that for all stems.

 

[Mcor]

Thank you.