The little one is developing well so far. The system sometimes has problems and the pH value drops to 5.3, which may be due to residues in the system, although it has been thoroughly cleaned. However, I have been working with a biological root booster from plagron. That could also be a factor. In future, I will no longer use this fertiliser for soilless substrates.
I have counteracted this a little with ph up from plagron to stabilise at 5.8 again