Thanks very much! ...Not sure if i should open a new question or not, but i just discovered i am also missing part of the venturi valve, so i want a replacement for that as well but am having the same issues. I found this
http://www.coralvue.com/otp-pump-air-intake-venturi but the one on the 100ss has more PVC to it to allow the surface skimmer to attatch... The pump is the OTP-1000
I bought this from someone who "lost the replacement cup and never used it" but its looking like it has been dropped. The black threaded part is what i am missing off the venturi valve that i have, but the replacement pictured does not look the same as mine.