Babushka Black and Blue Acid

First week and never had little plants struggling so much to grow. Not my first grow, but I like to change settings and experiment every time. So now I have to figure out what going wrong before is too late, if it's not already. They started very well and fast, untill the second pair of real leaves appeared. After then , leaves tips started to turn yellow, but in a strange striped way. Soil total composition is biobizz light mix (50L), peat (20L, ph4) ,perlite and vermiculite, worm compost (8L), bat guano (3table spoon), and some wood ash (a glass, to compensate the acidity of peat). Then I added slow release fertilizer vertafort (250g). My idea was to try not to add any nute for the whole cycle, so My guess is that I exceeded with fertilizers (my foult), So after only 4 days I had to flush all of them (that's the reason the soil looks so wet) and that stressed them out for sure. Now I lifted them from the ground to make the soil dry quicker. I did my research on other grow with similar problems but couldn't find a single one that looked similar. The strange thing is that they keep growing, not fast as I was hoping, but they are still alive. Ph is ok, between 6 and 7. Soil is still too wet Temps are 19 C at night, 24 during the day (grow box is warmed up) Please any help is very much appreciated Peace