Innovative marine fusion 20

[Valco213]

I have a new IM fusion 20 but am having difficulty in understanding tha filling up process and the water levels . On line there are various ideas even the I'm guide I find confusing.
Can anybody help to give me a simple guide.

 

[blaxsun]

Fill it with saltwater until the water level in the pump chamber is about 1/4" to 1/2" below the adjacent chambers.