I have the cascade 1500, not sure how many media baskets the 700 has but im guessing 3? And one of the media baskets should have a rubber ring around the top of the circle opening. Place the baskets in to the filter base aligning the open circles. There should also be a top(looks like a cut up tupperware lid). Place motor assembly on, and align circle openings with the hole on the bottom of motor, not the impeller. Hope this helps.