What is going wrong?

https://plagron.com/downloads/en/alga-grow-tds https://plagron.com/downloads/en/green-sensation-tds the tech specs on it don't list any Mg and Ca, soil typically has an abundance of these outdoors. Bagged soil may not be the same and a lot of them are comprised differently then the earth outside. And if its is available to the plants is another thing. You soil from images in your diary looks to be promix by plagron, its ingredients are peat moss and worm castings. Its lacking any aeration like perlite or vermiculite and I see this as a problem. I also find Peatmoss can become acidic over time and to much worm castings make it mud. Kind of a shit substrate in my opinion, If you added in around 30% perlite and treated it like soilless it could be ok. You should also link your diary to the questions for better access to information. growdiaries.com/diaries/249421-zamnesia-seeds-runtz-automatic-grow-journal-by-growinggramps/week/1386805 https://plagron.com/en/hobby/products/promix Worm castings can contain high amounts of Ca and Mg, however it all depends on what they are feeding the worms and how they where raised. they sate the medium has a ph and EC range so guessing its not a tightly controlled product. pH: 6.1 - 7.1 (1:1.5) EC: 0.4 - 1.1 mS/cm (1:1.5) You can and should use their grow schedule calculator. It will susgest/sell you more of their own crap, but you can use another brand that checks all the same boxes and does not cost as much. https://plagron.com/en/tools/grow-schedule-calculator It will only email it to you, so that's stupid, but guess it works to their advantage so they can spam yea later. They do not even recommend using alga-grow in their quick glance of things they advice when making the schedule. Odd. I find they have to many options and most of them are just trash from substrates to fertilizers to addativies. Its why I don't like this brand. They also have a bunch of BS about some of their products and claim it is liquid gold and "special carbon". Shity company and snake oil. Your going to want to add in something that is a more well rounded option for macros, NPK, secondary macros, SCaMg and micros, Might only need something with Ca and Mg as well as some microbes and or enzymes.