I recently upgraded my sump from glass to a more efficient acrylic sump, are there any concerns about the 300watt Eheim touching the bottom of the sump?
Get a Finnex 300 watt titanium heater it has a plastic shroud around it so it does melt the bottom of the sump or check outhttps://octoaquatics.com/ they make a heater holder with a magnet holder.