Ok, that explains a lot. Not a coco expert, but I know it needs to be flushed prior to use, unless it’s preflushed. Some of the premium coco is.
I thought your “soil” looked a lot like coco. Canna coco should not need flushing. It has no nutrient value for your plants so you must have nutes with every feed. When it is initially hydrated you need to charge it with say 1/4 strength nutes. And yes, soil nutes are fine but be sure to use a Calmag supplement. When the plants get older you will water to runoff. This helps stop nutes from building up in the medium. Never feed with plain water using coco. Shoot for a pH range of 5.8-6.2.
- get on the feeds ASAP, start at 1/4 strength and ease up from there,.. do homework on coco, it's not a true soil and cannot be treated like it or troubles will start soon enough,... Wtaer may be hard, but not necessarily have available Ca,.. do you have a ppm and pH of it? I'm afraid you won't like what you see on coco, it's very labor intensive vs soil, more like hydro in m=some ways.. typically in hand watered pots, you feed weakly, often, daily even, to 15-25% run-off; you test both pH and TDS/EC going in and coming out to make sure you are starting to get nute salt build-up; look into other coco growers for what ppm range to start at and go up to depending on their size,... be sure you calculate the ppm strength of nutes with what ppm's the water itself has, and if you're water is vert hard, it may not be suitable for coco use; coco needs to be around 6.0pH hard to keep there with hard water....
