Not much. Follow nutrient companys feeding schedule and usually thats enough. Im growing in soil and dont look after pH too much, like once in veg and once when flowering with all nutes in use.
With that price maybe Spider Farmer, Mars hydro etc. Check out that best deals threat!
I wouldn't really believe those Amazon reviews.
https://rollitup.org/t/the-best-deals-thread-post-best-deals-and-lowest-prices-links.237610/
No chance to go for 3 days in 1gal when plants are getting bigger and more thirsty. I think 3gal is safe choice. Depends of course how long u veg, lighting etc.
Why u just dont put seeds in riot cubes and let it pop inside? I think thats the point of these cubes. Seeds to cubes and in dome for couple of days, works everytime.