Can I Run two ducers side by side

I am buying a new Lowrance Elite 4 HDI and would like to mount it next to the older Garmin and run the transducer on the back of the boat, 25″ away from the Garmin ducer. Will this be a problem? Will they interfere with each other? I think they are on different frequency’s. The real reason for the purchase is the GPS feature. so both may not be running at the same time. The Garman is getting older and if it craps out I will have a replacement installed already. Any help would be helpful

Yes, you can do it, but you will probably get some interference, as they commonly run at 200khz for normal freshwater sonar. But it’s not the end of the world. I run a Garmin 250 and a HB 898 side by side all the time. Modern sonar units have a setting to reduce sonar noise, and it’s easy to distinguish what is noise and what is real echos. Noise looks like rain on the screen. Read the website below for the best info I’ve been able to find on the subject.

http://www.biggeorgiaspots.com/boats-and-electronics/62-other-stuff/180-aaargh-sonar-noise.html?showall=1