Why is my tiger lotus suddently shooting to the surface?

[LancsRick]

My tiger lotus has been a long standing member of my tank for a good few months now. In that time it has grown well, with a good red colour, and I haven't changed anything about light intensity, photoperiod, ferts or temperature. In the last week though, it's started to grow rapidly towards the surface. This is a bit of a pain since I quite like it being a low, bushy plant - I don't want floating lillies for shade. Picture below:

http://ukaps.org/forum/viewtopic.php?p=250950#p250950

Any thoughts on why the plant is doing this?

 

[darren636]

just trim the floating leaves. it will learn... unless it is a flower shoot?