Dave,

Best investment you can make for water quality is an aeration system. I would put it in in the Spring and begin to run it a little at a time until you work up to running it 24 hours a day seven days a week. You need to work up to 24X7 or you can cause a big problem. When we put ours in last June the smell coming up from the bottom was nasty. This from basically a brand new pond. You could poison your fish with that bad water from the bottom if you do it too fast. The smell will go away as you run it and your Disolved Oxygen will increase nicely. Another benefit will be that if you use the pond to swim you won't get the "slimy's" that you can sometimes get on your skin from anerobic bacteria.

Thanks for the comments on the web site. A hobby of mine. Designed it for my friend Scott from Catskill Pond who designed and built the pond for me. Will be doing an update soon if I can get him to move to a real hosting site. It's hard to do much much on a site that only gives me 10 meg. of space to use.