you are in coco. so you fertlize every time. it is a "soilless" grow medium. you do want about 30% perlite in coco, for future reference. improves root health and growth.
alays get 10% runoff waste. this is essential to maintaining a proper level of nutes in the medium. it prevents buildup of nutrients in substrate.
you can still overfeed if the concentration of nutrients is too high. shoot for 1,3 to 1,5 EC cooncentration of nutes (your water will add some too, but this is only about the fertilizer concentration)
you may need to adjust ratios of what is fed, but you want it adding up to that concentration range for mature plants. You may need more or less, but the adjustments from there are much easier to discern through plant behaviour. "fine-tune" it over time.
when to irrigated. in coco and in vege, i'd wait for the top layer to dry. it'll start to change color. also, feel the weight of the pot. if you water at the same loss of weight, it requires the same volume of water as before.
if you want to employ a frequent fertigation method, i'd wait until it is close to bloom or going into bloom. let those roots search for water those forst 3-4 weeks minimum. promotes more root mass and less risky with younger plants. later on you can water daily or even 2-3 times a day. i would hold off on this unless oyu do have at least 30% perlite mixed in. also the size of the plant and pot size have to match. the plant has to drink enough of the water in the pot before oyu can re-irrigate. if that is too slow, can't do frequent irrigations without damaging roots.
so, stick to safe and easy for now. can try more complicated stuff later. fertilize with 10% runoff waste water. wait for top layer to start to change color, then re-fertigate with 10% runoff... rinse and repeat
you still have to diagnose and adjust. not all fertilizers give you a perfect ratio of molecules. you may need to adjust until it works smoothly. some minor differences in plant needs early in life vs vege vs bloom, but no where near as drastic as you often see or read.