That Calmag will work fine. Thrive is great stuff but it doesn't contain a lot for plant food, it makes the soil more conducive to feeding so when you add the food it gets processed better. It makes the root zone healthier so better feeding can occur. That is referred to as a "soil conditioner".
It does contain a very light dose of food, but not enough. Looks like an excellent conditioner though
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The Biosys, that is a great tea, it also contains myco. Have you used it recently?
If not then after a watering or 2 with calmag you should use it. Just don't mix it strong. Myself I would go half or three quarter strength, unless you have used it already and the plants were happy, then mix it the same as before.
After you get those 2 in, say the day after the tea, I would use this as a top dressing
It too contains myco. Add a layer of topdressing as per it's instructions, then some EWC about a quarter to a half inch deep, work the EWC and top dressing ferts into the top inch of your soil, breaking up any crusting, but be gentle as you may encounter roots, and take your time and be very thourough.
Water that in but only with about a quarter to a half of the normal watering amount to rinse it in a bit and activate it all.
Then find a good fish fertilizer. One that says fish hydrolysate is better than one that says emulsion. Mix it as per the instructions and water with it on the next watering day.
Then start a routine. Use calmag every 10 days or so in place of a watering but otherwise add fertilizer topdressing every week, water back and forth between fish ferts and plain water, cycling the calmag in every 10 days.
Every time you water, check the soil surface 1st for crusting and break it up every time. After 2 or 3 calmags the crustiness should stop.
You do need to be aware that the top dressings will crust every time, but break them up once and it should quit. It is constant crusting every drydown that you are looking for. That's an indicator of low calcium.
Then if
@g-one-three doesn't mind, you should head over to his journal. He runs a system with Gaia Green dry ammendments that are very similar to the dry ferts above. He had a few small isdues that we tweaked and he has it working really well now, so he can help you prepare your next batch of soil to ensure you don't run into this again. His last grow and current grow would be very good reads for you, and he's a regular in here so he's likely aware already of your issues.
If you need guidance or are still unsure please ask immediately, as it's better to ask than make a mistake.
Let us know how it goes. Post pics in here every 2 or 3 days if you like so we can watch your progress.
What you are dealing with is pretty common in small pots so don't despair, they can be saved, it's just going to be constant maintenance on your part.
Small pots are excellent practice devices lol. Once you go to big pots it will feel like a vacation.