Can I use this as a top dressing ? If yes, do I put it on top before or after watering ? Sorry if this seems daft, I'm used to bottled nutes

It will effect the Ph but personally Id go by what it says on the bottle and dissolve it into water i use this for rooting clones it is a very powerful root promoter my best advice to do a lil bit in a glass test the ph then adjust to what you know the ph to be in your soil or coco then just add it in the next feed top dressing would probably not be the best option but if you intended to water or feed straight after it wouldn't really matter its completely up to you :) All the best buddy