Keep in mind that using only one bag per post is only 80 pounds.Thats like having a fourth grader holding up your posts in a strong wind. I would use two per post even though using only one is very common.Dipping the post bottoms in tar before setting is a good idea but cedar is pretty resilient anyway . Also I would mix the concrete before pouring it in the hole as opposed to dumping it in dry and flooding the top with water. Just my personal opinion.There are several ways to do a good job,this is just one of them!

Looks good.If your plants start to get leggie then it may help to lower the light.I usually start mine with the light just 3 inches off the soil.

That or you could just buy the underlying asset ( BTC) and hold it longer than a year to get clear of the short term capital gains tax.