Yahoo! I got my new aerator today! Now I have a couple of questions.
It came with a styrofoam float, do I need to use it?

The instructions say it's a good idea to replace the air stone once a month. Is that necessary?

This is the one that I ended up buying: http://www.aqua-mart.com/lpt1630.html

Thanks :D

I found that the styrofoam float didn't work that good for me, it kept floating into the corners of the pond and staying there, so I just put my tubing over a board so I could keep it from touching the bottom. This worked so well that I did the same with with my new big aerator (which I am loving by the way) I used mine for about 5 months and never had to replace the stone, I wouldn't bother replacing it until it starts plugging up or it starts to crumble. It would be a good idea to have a spare or two on hand though. ;)

It says the float is to adjust the depth of the air stone. If so, and you just want it on the bottom of the pond, you wouldn't need it. I put my air stone on the bottom and even wrap some aquarium lead weights around it so it stays sunk and in place somewhat.

I try to replace the air stone on my Tetra Luft pump yearly but now nobody carries the one I need anymore. AquaMart used to find a few in the back of their supplies but I guess they ran out too. I may have to adapt some other kind of air stone if they fall apart enough. The air stones literally fall apart over a few years. Replacing it once a month sounds funny to me!