I add a drop of fertiliser the night before regular water changes, adding phosphates and nitrates and such (for the Nem), and use carbon dosing to rinse it back down to zero.
That way the Nem gets its trace elements and I get it back out before too much algae growth can prosper from it.
The Nem seems to be "puffing up" on the first pictures, stretching extra for light and act more "normal" on the later pictures. All sources say to give it food more often (up to every other day), until it rebalances it's inner algae growth to its new surroundings and it should recover just fine. People say it takes about 1-4 weeks.