What to do?

[Voylike]

Just a quick in guys, do I trim this back to where it is healthy again at the bottom, and if so why has it gone like that in the middle? Thanks

[fr499y]

looks like algae or diatoms which can happen if the tank is new or there isn't enough flow in that area of the tank.

[John Linklater]

Rub them with your fingers gently and see if it comes off. I had a similar thing with that plant (sessiflora I think it’s called) and it was some sort of algae that came off. Be careful though because if you do it too hard the leaves will come away.

[SPACKlick]

As the leaves at the top grow they shade the lower leaves which will then be perfect locations for algae. Depending on the rates of growth and flow in your tank you can either clean the leaves or trim and replant the tops and compost the middles.

[Martinspuddle]

Not powerful enough lighting and nutrient deficiency are the usual reasons stem plants do this, allowing algae to take hold on the weaker part of the stems.