The 65 WDG on seedworld is enough to last a home owner with say 5k sq ft AND applied at the Maximum annual rate every year so many years they will likely never finish it in a life time. And that's max rate, and with shorter Canadian seasons max rate might be used first time. I didn't ever use max rate because I like to overseed a section each year seed down mid to late August...so no more than 4-5 months of protection is ever needed.
I use seedworld too much, I got addicted but the quali pro 65 WDG is probably the one thing I would get. With the prodiamine all the money I spent ordering post emergent herbicides was basically not needed because I get hardly any weeds. I would get prodiame and the smallest bottle of speedzone and your done.
The time saved on were control, the greener grass with no weeds taking nutrients and sunlight, the yellowing stress from most weed killers.....or paying someone to treat weeds will cost far far more money, time and stress than 1 order of the 65 WDG prodiame and you get a nicer lawn.
It's so worth it....and I was nervous the first time i ordered. It's so ridiculous now to me after getting accustomed to ordering.
It's not that expensive and now I can give my father some every year and even a Christmas gift for a friend into lawn care and still know I'll never use it all.