Hello, I am currently on day 12 of growth Do you think I should use any other fertilizer besides root fertilizer? Thank you for your comment.

The root tip of a seedling is crucial for finding nutrients, helps if it can find what it needs to grow, soil EC of 0.5mS/cm is ideal for a new seedling, Phosphorus (P) is essential for early plant growth. A lack of phosphorus during this critical period can severely restrict root development, leading to poor crop establishment and reduced final yield, highlighting the need for adequate P availability from the first stages of germination. I always add an extra dash.

depends on the medium -- soil can have a wide variance in nutrient content. If it's 'soilless' you need to be providing a well-balanced diet from the get-go. even though not mentioned, can infer that this is soil since i don't see deficiency signs starting by day 12. Not all soil is the same.. might takes 2-3 weeks might take 8 weeks before you need to supplement it. The levels of each nute can vary too, so can't even tell you what will run out first. you'll have to learn that .. ramp up supplementation as the soil's amendments are exhausted. if you stick to same products, will be similar ramp up.. similar timing when various nutes run out.. can work out a pre-emptive plant to avoid all issues easy enough with a little effort over time. Take notes.. i'd add perlite to it in future. including what came with the soil, 'drainage' amendment should be roughyl 50% of the volume for optimal drainage and aeration characteristics. In a light medium like coco, only need 33% of volume. In the end both will have similar water capacity per volume at these ratios -- not an accident and the whole point of the difference. (don't worry, it won't derail grow, just less risk, better growth if you do in future)

They are looking nice! I noticed my plants at this stage love some (pure) coconut water ,then compost tea a week later. worm casting top dress a week after that and some kelp, and maybe cal-mag. a simple 4-4-4 or something to start happy frog fertilizer, dr earth or gia green work well for me.

Fix ur Ca issue first )

Worm castings works wonders, a particular brand "Wiggle worm" 😎