I grow in either happy frog or ocean forest soil mixed with perlite. I was thinking of adding a little boost to these soils with bat guano, castings, or both! Should I mix them into the soil or use as a top dressing later into flowering? Worm castings would better mixed into the soil correct?
personally I wouldn't advise to add guano to the soil... castings YES, guano, no.
If you really want to add something like that, i'd recommend neem meal, crab meal, or rabbit manure, but do so sparingly the soil is already fairly amended with nutrients.
You did say you were thinking of a topdress during flowering, i'd lean more towards that, as opposed to adding extra guano to the soil when first mixing.
A topdress of EWC and either a guano, or a manure, good topdresses.
So in other words, if you want an extra nutrient for the soil mix, i'd add rabbit manure, neem meal, or crab meal... I also like insect frass.
but for a topdress most of those ingredients won't breakdown fast enough (the rabbit manure will), so for a topdress it would be best with a mix of EWC and guano
