Too much nitrogen, how should I continue fertilising with BioBloom from Green House Feeding ?

4-9-9? image is a bit iffy reading it. the problem with this ratio is that you will either have too high of P or too low K. 1-1-2 is a better rough average.. expect to deviate a fair amount as these are heavily rounded. if in soil, you'll need more N due to the source of N needing microbes and such to make it plant ready. This ratio is for 100% plant-available ingredients. Some translation needed for soil context. for a proper amount of P at roughly 50ppm, you have 50ppm N and 100ppm K... Even 50ppm of N would be too little in flower, but as you correct a toxicity, this would be fine. For a proper amount of K at roughly 180ppm - you have roughly 100ppm N and P. The 100ppm N is probably fine, but 100ppm P may run into issues over 8-10 weeks, if not initially. So this might be tolerable. a better mix of products would be 5-5-9. If you could get a weighted average by mixing in another product, this is very doable. You may need a bit less N in flower and if combating a current toxicity issue. but would be great in vege in future and should avoid that tox, whic means you can simply drop N in first week or two of flower and never see a toxicity from it. 4-4.5% - 5% - 9% NPK (USA standards for labels) would probably do well for flower... again this is for 100% plant-ready nutes.. any magical soil nutes that require 'something' to help breakdown the ingredients to enter the plant will need some translation for that extra, useless step, lol..

Use less of it. or use less of it and add in a PK boost. Don't forgot the secondary macros like CaSMg and micros. Mg can also influence N tox, but the plant still uses a good amount of N in bloom. Just a bit less then in Veg, it is still a macro nutrient vs micro. I find some bloom fertilizes lower the N to much. I saw one that was 2-7-7 and that's just not enough to me. You could also try giving it a nice flush now that your switching to bloom and just wash out any extra N kicking aorund in the medium. Assuming that stuff is a fast dissolved salt based fertilizer and not a slow release dry amendment. Good Luck!