When the older growth on bottom is yellowing but there is some new growth on top still green it really is a strong sign that its lacking nitrogen. Guano, as great as it is for organic gardening, requires bennys and time to be broken down into a usable form of nutrients for your plants.
Give them something they can drink up quick with a couple of ml's of Humex, wow do they love that stuff and bounce back strong.
Give them something they can drink up quick with a couple of ml's of Humex, wow do they love that stuff and bounce back strong.