Fiem 140/200 hatcher have severe problems with keeping humidity

We have covered almost the entire bottom of the hatcher with water basins and can still not get the humidity over 45%. It is spring time, May 9 2023 and the relative humidity in Södermanland, Sweden at this time is 33 %.

We just finished a hatch and have taken out the chickens and filled one basin with a little baking soda to release calsium from the float switch to have it operate properly. After that we will clean the hatcher for the next round of chickens hatching from their eggs. We have 5 days between hatches. The chickens hatch alright but are having problems with egg shells and amniotic sac residues stuck on their body. And some needs help out from the eggs in the end due to the eggs becoming to sticky.