I think that you've got a Mg/ph/micro deficiency,guano is tricky stuff to use if this is your first attempt at growing,it's usually used as a soil amendment or steeped for hand feeding,until you become a little more familiar with what you're using,save yourself a little frustration and get a complete hydroponic nutrient fert,the plant does not care if it's organic or chemical,nitrogen or phosphourus is the same to the plant regardless of the form it's in,I know a lot of folks swear that organic grown is a better product,but in my experience growing in soil or hydro i've seen no difference in the final outcome,as long as you use the proper techniques when it comes to knowing what the plant needs and when to flush and how to cure,hydro nutes work great in soil grows too....bonbon