I've found that using BioBizz Light I need to start feeding (using full strength) after about 2 weeks or even less. Using ≥4 gallon pots, the plants can go 3 or even more weeks without actually needing watering. But starting at about 2 weeks, I add enough feed water to keep the soil wet/damp with no drainage, with this lowly increasing the concentration of nutrients, the concentration going up as the original water is consumed or evaporates.
So far, this is working for me. I'm in a fairly standard setup - small tent, AutoCOBs, 4-5 gallon pots, etc. I am using only Adv. Nutr. Connoisseur Coco Bloom (modified TaNg method) or 2-part MegaCrop from the very start to end. In most recent grows, I've been using 2 g/L (1/2 strength) Adv. Nutr. Connoisseur Coco Bloom with minimal supplements (microbes, kelp, enzymes, sometimes P-K boost in bloom). I do not add any calcium, magnesium, and have stopped all foliar feeding (see no need), which I used to do several times/week in coco.