BIG GAS LEAKZ homie, i had a similar issue as i saw my plants having yellowing leaves that started from the saw edges rather than the tip or all the leaf , some yellowing is expected at flowering but no with (this shit was more bonekiller for me! ) tiny brown holes that look like if they were done with a mechanical pencil lol, in my case i thought that was a CaMg defficency and fucking nailed it my plants are recovering , i know u are using a calmag according to your brand , and a hell of lot nutrients but i see some redundancy between fish mix and bio grow as both are reccomended for vegging and in case of flowering , with discretion or when required as overfeeding can cause nutrient block as well, as +16ml (i understand that from the question ) , but still +8mt from the journal record itself is still a lot of different liquids seems too much for plant and container size water . i tend to water at 1:10 ratio, if i had to water a 15lt container, i would do it with no more than 1,5 lt of water, and with that see how much nutrients mix can i do without making it too strong for the plant stage it's living.
I don't mess with EC measurementst oo , but i stick to nutrient schema provided by each nutrient manofacturer i use ( i fucking mix a lot of brands chief but for you should be easier if u ase biobizz plan !) As yellowing from bottom to top of the plant is natural as plant consumes it as a reserve like our tummy specially on flowering because demands more , when it happens to middle to upper leaves , including other symptoms like hole on the plants when the reason is not plague.
Less is More, as is more easy to correct a carencie than an excess !