Thanks Simon, that's helpful. I have moved them yesterday and think they will get more flow now. I am used to plants doing badly – pale, leggy, losing leaves – but what surprised me with this one is that above the sand it is fine, but when I remove it the stalk has rotted below the surface, so it really does have the appearance of a stalk responding badly to what it has been placed in. I have some sessiflora – my first plant, whereas the aromatica was only planted 4 weeks ago – which was doing very well, but recently became pale and thin, so I think that's an indication of lack of nutrients. It does get flow. I have been doing standard APS dosing but will try raising that. I've recently tried adding some iron as well. I had reduced the light from 12 to 8 hours as I had a green water issue. I don't think light is the issue with these plants. The flow in my tank is pretty good as the tank is low, 15 inches, and I have a spray bar at one end and an Eheim pick up at the other. I have to buffer the pick up a bit as it's so powerful.