I think you should consider an aeration system too. That smelling fould water coming up from teh bottom indicates Anaerobic bacteria at work. That is a bad sign for fish. This would indicate a low dissolved oxygen.
You will need to run it a little at a time if you have fish in the pond already until you clean things up by getting the water circulated. I would do an hour a day for the first week or 2. The smell will be pretty foul down wind. As the smell starts to dissipate that will mean your water is getting healthy and you can run it longer.
We run our aeration system 24/7 from ice melt until first week in November. We have no slimey water or smelly water any more.
