What were your biggest purchase mistakes?

[Samw]

Originally Posted by lastlight

Tunze 9002. I fell for the hype and failed.

+1 on the skimmer.

Another mistake that I can think of right now are buying Acroporas when my water quality was poor. Wasted most of my livestock money on those by far.

Also wasted money on various MH single bulb setups and pendants when in the end, the dual 150w HQI was the better choice for my system at the time.