I have a possibly stupid question, about how much granule type fertilizer to use particularly for azaleas. When considering the ratio on the back of the bag or bottle of your average brand, it doesnt account for a Bonsai pot holding only at times a tenth of the recommened soil amount,so other than trial and ERROR! When you need to feed and cannot take a chance how do you know how much is too much. Thank you in advance.

first thing first azaleas are acid loving plants so you will need something like miracid which is a water disolved fert for these plants.
second thing the soil needs to be wet when feeding azaleas. i found this out the hard way and killed mine .they are very suseptable to salt damage their roots are very delicate.
rule of thumb for fertalizing bonsai with water disolved fert is to use at half strength,so if the directions say 1 tbl spoon per gallon of water use 1/2 tbl spoon simple as that

as for granular fert i cant recomend using just because i havent used it on an azalea ,but my other trees i usually just sprinkle sparingly even tho i have found heaps of it in nursery plants i have purchased.

thank you, have been trying to apply coffee grounds to soil to assist with acidity. granulated has been vigoro for azaleas but I will try liquid muracid. I have a bountiful supply of 10 or more year old outdoor azaleas from my neighbor that I can pull up and keep learning from Though I feel awful when they die.