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found this on ebay... anyone have any experince or thoughts on it?

http://cgi.ebay.com/ws/eBayISAPI.dll...m=160083893216

Not to get into the +/- of overflows, unit looks like a CPR clone
http://www.cpraquatic.com/products/overflows.html

I have that exact unit and it's been working fine for several months now on my 66 gal.

wow - That's VERY nice, and an amazing price!

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As mentioned, looks like a CPR clone. I have been running a CPR for 3 months now, and haven't had any issues at all. Looks good to me.

Just keep an eye on the pump. It's probably a cheapy. If it craps out, you'll lose siphon and end up with a lot a 'splainin to do with anyone who you live with.

Is the pump to maintain siphon? I thought it was just to start it?

Starts the siphon but also sucks out any air that might build up which could cause the siphon to break

No, but man is that ever a common misconception!

Having the pump there certainly makes starting the siphon a lot easier, but it's real value is ensuring that the siphon never breaks.

As the siphon runs, tiny air bubbles get pulled through the siphon and can accumulate at the highest point. If they are allowed to accumulate too much, they can break the siphon.

The pump creates suction on the top of the siphon, removing this bit of air whenever it might happen. For years, I actually ran the pump on the same circuit as my evaporative top off...meaning that the pump would only activate every hour or so. (sort of a random wave maker) You'll see the pump spit out little air bubbles every so often.

Personally, I wouldn't run a siphon of any kind without some sort of similar air removal system.