My first coco

Think it's multiple deficiencies. Also, refer back to my answer of your first question a week ago. The EC you mention is including tap water contributions, so it's even lower fertilizer than it seems... unless you are using 0ppm RO water or something? If that's the case, pH lockout is potentially hindering things.. the nutrients that struggle first with low pH are Ca, Mg, and P. K and S won't be far behind that. N may even need a bump to mitigate it. PPMs N 120-13 P 40-60 K 180+ Ca 100+ Mg 75ish S 100ish I'd suggest starting somehwere near there. If anything is drastically different, i'd wager that's part of the problem. This ignores anything added from tap water. Adjustments from there to balance out with the environment you provide will be minimal. Do need to drop N in flower, but i'd wait and see as it recovers before blindly doing so. in flower, drop N if it starts to get too dark green. EC converted to ppm is incredibly inaccurate. Just by using 500 or 700 scale it'll be a 40% different conversion.. for no other reason than the equipment you are using. If in US it'll most likely be a 500scale conversion but in europe i beleive 700scale is more common? 1.25EC might be 625ppm or 875 ppm purely depending on the equipment you used. Also, your meter is including whatever EC your tap water adds... Fairly cetain you are just feeding too little. No pH lockout, but 6.0 pH target gives more room for error. Also, your mix and runoff hints that it's slightly higher than your mix in the medium, or trends that way between fertigations. There are free apps and websites that will convert gauranteed analysis labels to ppm.. A simple google or app store search should find them. Think one app is called hydrobuddy that also has a web site option. One concern is labels of NPK are not always the same.. Think UK does one or two differently, possibly europe in general? Make sure to account for that if necessary. Any calculator i've found worked with the american labels. Make a spreadsheet of your own if you have the technical skill. https://en.wikipedia.org/wiki/Labeling_of_fertilizer