Mangelerscheinung?

Biogrow has a little nitrate in it so it has enough to initially feed but majority of its nitrogen is organic.

Biobizz organics. Feeding organic nitrogen 3 weeks into flower. Growing organics comes with a couple different things especially as flowering kicks off, mostly to do with nitrogen. In a synthetic grow we would use nitrogen derived in its final form of no3- . Readily available and easily leechable. Very easy to control nitrogen and whenever the times comes in flower it just washes away triggering plant autophagy and the recycling of nitrogen. How does it change for organic? First you need to understand what organic means. Organic matter is anything that is not broken down into its final form and requires time and microorganisms to spend weeks / months breaking it down. The breakdown of organic nitrogen is called nitrification and the rate of conversion is strongly linked to ph. At ph of 6 or below nitrifcation practically ceases and nitrogen will be converted to nh4+ But not no3-. Who cares? Ph does. As organic nitrogen break down it first breaks down to nh4+ then it's final form of no3-. As the plant starts to need less and less nitrogen the orga ic nitrogen doesn't care and just keep releasing more and more nitrogen. This skews nutrient ratio. This skews ph dramatically depending on what the nitrogen is converted to either + or -. Nitrogen and its content within the soil is a strong signaller for floral development along with the carbon content. Flushing might seem like a option but you need to remember no3- is highly mobile ND flushes readily, but nh4+ sticks to soil particles like glue and requires much much more leeching to get it out the soil. Flushing out nitrates without getting rid of nh4 then resetting ph back to 7 will only accelerate nitrification 5x,6x if organic nh4+ is not completely removed. Honestly new growers stay the away from organic nitrogen. Until you graps the finer details. Only going to cause problems.