I'm no expert but if it were me I would put one fuser at about the 15 foot mark and one at the 8 if your going to have them separate from each other. Then you could always pull in the 8 foot deep one and use it in winter at about the 3 foot depth to help keep a nice hole in the pond for winter.
That's just me tho. Lets see what other have to say that know what their doing.
![smile smile](/images/graemlins/default/smile.gif)
RC