First off.. dont auto feed your plants unless you are running a hydro system... especially if you are growing in buckets.. your plants will all grow at slightly different speeds.. and some may need more/less watering than others depending on where they are in the garden etc. Second.. I like Sunshine mix #4.. initial runoff ph is PERFECT for cannabis! Third.. stick with any 3 part food... I prefer General Hydroponics Flora Series.. I find its usually one of the cheaper brands.. and it is also one of the more popular ones.. Use the feeding chart they have on the website (your grow store may also have paper copies). I also HIGHLY recommend foilar feeding with "Growth Plus".. spray every day at lights on.. stop 2 weeks before harvest... and I would also recommend a B1 vitamin like "B-52" from Advance Nutrients.. or "Vitamax" From Grotek.. Water with small amounts every day (quick count to 5 on each plant) And feed them straight Ph'd water every third day to keep the salts down in the soil.. Some guys will tell you its ok to drench the pots and leave them for 4 or 5 days at a time between feeds.. but I have found MUCH better results with watering small amounts daily ;-) Good luck!