What type of spreader?

Do you know of a setting you've used in the past for a similar prill size ?

 

Is there any instruction on how many lbs per 1000 sqft? E.g. like 4 lbs / 1000 sqft.

Normally I would measure out the weight, put it on the spreader and run it through the spreader until everything is gone. After doing this few times, you will get a good idea what spreader setting you should use if you want everything gone by just walking once on the lawn.

 

I found the following which says 4.6 lbs / 1000 sqft for Prodiamine 0.5%.

https://regalchem.com/wp-content/uploads/2019/03/RegalKade-G-Sell-Sheet-Web.pdf

From another calculation:

The Prodiamine 65 WDG (65%) application rate is 0.4 oz / 1000 sqft
Since your product has 0.5% Prodiamine, then you need to apply 65/0.5*0.4 = 52 oz / 1000 sqft or 3.25 lbs / 1000 sqft.

I would guess you need to put around 4 lbs / 1000 sqft.