I've been growing Fastbuds in 3 gallon felt pots. My latest plants I put in 7 and 11 gallon pots. In 3 gallon pots my plants are huge anyway but I figure the roots need more room and I have to water more than once a day in the 3 gallon pots with my plants so big. All my Fastbuds except Fastberry are huge plants, bigger than their website says they will get.
I'm currently using Fox Farms Happy Frog but in a couple grows I used the cheapest 40 pound bag of potting soil I could get at a hardware store and grew a Gorilla Glue from Fastbuds and it grew just as well as all the other ones I planted in Happy Frog. I'm drying a Mexican Airlines right now that was planted in cheap soil I mixed up with Coco Coir and it looks to be my biggest yield. Also drying a big Pineapple Express that had a huge central cola that I had a bit of rot on. Have two Fastberry plants almost done, lost two others, they were planted in a mix of Happy Frog and Ocean Forest and the two I lost were stunted and not worth keeping. I also harvested an LSD-25 and planted two more of those along with two more Gorilla Glues. I also grew one Rhino Ryder from Fastbuds.
I got my Fastbuds seeds from
https://dankseed.store/genetics?olsPage=products
They had a 5+5 sale but now they have a buy 2 get 1 pack free.