Honestly I don't know much about that skimmer. I do know that I have wasted about $130 on a skimmer similar to it and wished I had saved more for a far better one like the Euro-Reef RS 135 I have now. $300 for it but worh every penny IMO
. I have learned that in this hobby you get what you pay for. If it is cheap then most likely it is "cheap". For a 40 you would do well with a Aqua-C Ramora back pack style skimmer or something along those lines. I'm sure that others will have suggestions as well. Looking forward to seeing some pics of your setup!!!!!!