Eichhornia crassipes problem

[Svein]

Hello
Hope I can get some help here, I have several of these plant and they have grow very well, and I have got a lot of new plants.
But now it has stopped, the roots still grow, but I have got a lot of brown marks on the leaves (picture)

I'm using hqi as light source, using 10ml to 100l with plant nourishment, and in fact I haven't change anything from the start.
So if anyone can give me an idea, I would be greatful!



Regards
Svein

[PeterGwee]

Seems like poor NO3 to me. Do you supplement any form of nitrogen?

Regards
Peter Gwee

[Svein]

Thank's Peter
Yes I have nitrogen in the mixture I give, but may be I have to increase the amount. I have to experiment a little.
Regards
Svein