So an update is in order. I switched as planned and I think it went well, all the fish and shrimps are alive! Picture is 1 week on.
I guess it doesn't look like there are that many plants, but there are over a hundred individual cuttings and plants, I hope that's enough and they just need to do some growing!
The plants are: Rotala Rotundifolia, Anubias Barteri Nana, Limnophila Sessiliflora, Echinodorus tenellus, Sagittaria Subulata, Hygrophila Corymbosa. I've also added Amazon Frogbit since to help consume the Nitrates.
The water parameters:
Ammonia 0
Nitrite 0
Nitrates are a bit high, between 40 and 80ppm, but my tap water has about 50ppm according to my water supplier.
pH has gone down to 7.4 from 8 before the switch.
Hard water: 100 mg/l or 14.01 German deg.
I started to see some green hair algae on the glass, so the good thing is there is food for the shrimp but might be a sign that there is something not quite right.
The lights are on for 5 hours, then off for 5 hours and back on for 5 hours, so I wonder if reducing the lights would help to control algae. Is there anything else I should try doing?