I didn't realise you could use molasses in Coco, maybe I should test it on just one of my six ones and see what happens
Yes, the plant cant take in some carbohydrates but for our purposes we want the root biome to continue making nutrients. Without the carbohydrates shared by the plant the biome "goes to sleep". The root microbes eat the carbohydrates for energy and then produce the ions that feed the plant so many other nutrients that the plant cannot produce themselves. If you have light, Co² and water the plant will produce it's own carbohydrates but it stops sharing them with the root Biome.So whthout carbohydrates meaning less energy, so If an easy source of carbs ie molasses brocken down provides the plant with energy to continue to grow flowers at a sustained rate then
If your coco/rock wool have not been overly flushed you will have an extensive root biome alive with many microbes that are actually initiated by the roots themselves. It is part of what makes these media so successful. I inoculate my rock wool at transplant with Mykos to give this process a head start. I started doing this many years ago when first doing some hydroponic lettuce because of my background in organic gardening. It was like old farmer Bro-science it works in soil why not hydro? It turns out I was doing the correct thing as science has proven that the plants themselves will create a robust root biome. So even if you only feed salt based fertilizers the plants entire life in these inert media the microbes are still present. When the plant stops sharing carbs we step in and feed the biome.Depends on why you are ising it.. Are you using it to feed microbes in the soil? Or are you using it as potassium boost? You didn't list any microbe source so I'm unsure if you have active microbes that the molasses will feed on. Week 4 of flower of a photo period plant is a little early for a K boost bit if your plants are healthy it can't hurt.