What, no safety wire?

Welcome to the forum Barry, glad to see another aviation buff on here and not far from Oshkosh.
Nice looking pond and very interesting aeration set-up you've built, I too have a small linear pump for my pond but using a soaker hose for aeration in shallow water.
What species of fish do you hope to stock in the future?
I think your system would be ok for that size pond but you should get more info from people with lots of aeration knowlege soon.
P.S. What type aircraft are you building?