DL, I think that the cascading action of the creek is probably enough to keep oxygen levels high enough to sustain your fish. This is coming from a guy who represents a company that's been selling aeration tubing since 1992...We would never specify it for your application.
I can't speak on behalf of Canadian Pond aeration tubing but ours does not foul within a year. Even if it did, cleaning it is as simple as pouring a cup of muriatic acid in the tubing from shore. We have linear aeration systems that have been in operation for over 30 years. Also, it takes about 2 PSI to open the slits in the tubing which gives us wiggle room of about 2.5 - 3 feet of depth difference over a single length of tubing and we'll still get a consistent bubble pattern. This is one of the big differences between aeration tubing and irrigation drip tubing that people use for aeration.
This is not a shameless plug. I just want the pondmeisters to know that there are differences between different types of aeration tubing. We've got ten different types of aeration tubing in our product line alone, each with different specifications (air flow, internal diameter, bubble size, etc...). If you're thinking about linear aeration, contact some vendors, express your questions, comments, and concerns, and ask for recommendations and the specifications of their particular tubing. Make sure the product fits the application....I guess the same could be said for any product.
