Waterway 3/8″ Top Flo Air Injector, 670-2300

This is the Waterway 670-2300, a 3/8 inch air injector from the Top Flo line. It is the genuine Waterway part.

Installation size

The injector needs a 1-3/16 inch hole to install. That is the one measurement to confirm before you order, because an opening cut for a different injector will not let this one seat and seal. The 3/8 inch in the name refers to the air line the injector takes, not the hole.

When to replace one

Air injectors live in a hard spot: constant wet, constant air, and whatever the water chemistry is doing. They scale up internally and eventually crack. The symptom is a weak or uneven bubble pattern that does not come back when you open the air control or clear the line. At that point the injector is the part to change, and swapping in a fresh one restores the pattern without touching the surrounding plumbing.