using the water, feed idea in soil seems to create problems. People tend to feed too much in soil. the fert stays trapped in the soil. better to just put them in ocean forest or happy frog and avoid feeding unless you're sure you have too. a supersoil mix and just add water is also a good idea, but you have to let the soil sit for about 2 months if you mix it yourself so the bacteria in soil will break the material down. Using bottle ferts is dangerous if you don't know what you're doing. People over fert.