You have your pipeline design from the last unit — a sketch of how the steps connect.

Don't look at it as a diagram. Picture it as plumbing: every connection is a fitting the flow has to pass through. Where pipes meet tight, water runs clean. Where they're joined in a hurry — it drips.

Run each joint of your design in your head: which one honestly looks like a temporary clamp held together with tape? That's the fitting to reinforce before you turn the water on.