Conseil coco, perlite et autofloraison / nutrition.

coco has zero nutrients, so you need to fertilize every irrigations -- can exclude the initial irrigation when germinating/sowing seed. From now on you need a well-balanced 1.2-1.5EC concentration feed. Fertilize every irrigation with 10% runoff - this is waste water. It is fine to reuse in an outside garden but not potted plants. Ratio of the nutes is just as important as overall concentration. PPMs calculated from guaranteed labels N 120 P 50-60 K 180-190 Ca 100+ Mg 50-75+ S 100-110 Apps can do all of this math for you simply by enteringn percents off labels and dosing proportions. These numbers are not meant as anything more than a good starting point. Observe and react to the plant, as it will decide what is correct. Your local water will contain some Ca, for example which may require some more or less from your fertilizer than someone else. Early on wait for the top layer to show signs of drying. A more exaggerated wet-dry cycle will grow thicker roots and promote deeper roots vs superficial roots. After the plant is drinking down the water from the pot faster, you can consider more frequent irrigations with coco coir + 30% perlite. The first week of flower/bloom, you may want to drop your N ppms to 100-110. Whether you do this the first week or a week or two in really depends on asessing the darkness of your leaves at flip to 12/12 (bloom) light cycle. As long as your nutrient products are all 100% plant ready and 100% soluble, as they should be for soilless context, then all will go well. pH to roughly 6, +/- 0.2. white distilled vinegar will work well, or if you buy good "hydro/soilless" fertilizer, it should be pH balanced on its own. I don't know of brands in europe. Masterblend J.R Peter's Jacks Hydro Part A southern ag athena flora flex Probably others... these all have a "hydro" or "pro line" of dry nutes that essentially add up to the PPMs i listed above with very little deviation between them. This is no accident. It's a science-based formula from extensive research that more than one company makes use of. The base product is paired with calcium nitrate and epsom salt. If you see something similar to that setup, it's probably based on the same knowledge/research.