I started cheap, need to upgrade soon for this bigger tank. Link to the one I have: http://www.amazon.com/Protein-Skimmer-Counter-Current-Medium/dp/B0002APZ8U/ref=sr_1_6?s=pet-supplies&ie=UTF8&qid=1453951053&sr=1-6&keywords=protein+skimmer It has worked well, the comments about it being finnicky getting set correctly are correct, but once the airflow is right it does a great job.