“I purchased this to replace my old workhorse Eheim Universal 3400. Nothing with with the 3400 other than it was getting a bit noisy and will remain with me as a spare. The location and spacing of the inlet/outlets along with the thread sizes, are identical between the Universal 3400 and the CompactOn 3000 so it makes for a perfect ‘drop in’ replacement. The 3000 runs so much quieter! I now have an Ehiem CompactOn 3000 and 5000 running side by side and their are both extremely quiet together.”
