I grow in a balcony and i never hand pollinate flowers.
I use generic soilless from store
I use water that ware stand for 2-3 days, that bring the PH from 7-7.5 to 8.5-9 and I never fixed the PH
I found (for me) that over fert is the main reason for flower drop
2-5/1000 (as describe on...