Fish for cycling

[Roberth101]

https://www.reef2reef.com/threads/d...ltwater-tank-quickly-macna-2019.659914/unread

I watched the video and checked out the product. Looks good and i am definitely going to use it. The thing that i am wondering is, the instructions say "add 2 cap fulls(10ml) per 10 gallons of water." 10 ml per 10 gal for a 75 gallon tank is 750ml. 750ml=2.536oz. Everywhere you can buy the product says a 4oz bottle will treat 60 gallons. With the math above, providing it is correct and i am sure it is. Wouldnt a 4oz bottle be more than enough for a 75 gallon aquarium?
On a side note a 2oz bottle is $3.77 and a 4oz bottle is $19.60, doing the math = buying the larger bottles is waisting your money. IMHO.