How much should be the humidity? And how muck nutr...

Well, as for humidity, if you can keep it below 60 you should have no problem with bud rot (that's my usual level). If it's higher than that you can defoliate a bit and that will help. As for biobizz, I use that too and biobloom is fairly mild, so 1 to 4 ml/lt is fine, just follow biobizz schedule. I no longer use topmax since I didn't find any difference while using it. What has helped too is keep using biogrow in flower at 1 ml/lt. Hope that helps

Hi, Optimal Humidity is 40-50% RH (or less). Ideally, the relative humidity of your grow room should be lowered to around 40-50% at the beginning of the flowering stage. As plants approach harvest, some growers lower humidity down to 30% or even less to force cannabis buds to produce more resin. As for feeding, start with half or even a quarter of the recommended dosage per litre of water. The key is slowly coming of N (Nitrogen) while giving it more phosphorus (P) and potassium (K). By week 3-4 flower you want to of completely come off Nitrogen altogether. But so early into flowering, loads of nutrients isn't a must. In fact, less is more and gradually increase the dosage little by little. Thats key, don't over do it as you will run into more problems.. You can always add more but you can't always take out. There should be a feeding schedule on your nutrient lines website (have a look) half their dose or maybe even quarter and start there. Hope this helps. Good luck.

Looking at your buds, I think you can go below 50%...