Best HOB Power Filters, EVER!
If I had the $$$, I'd have Four ac110/500's on my 135gallon! The current Two do GREAT right now!
Even the ACmini took care of my 30gallon with an overstock of cons a few months back!
Not true. I have an ac30 (on a 10 gal sw with stricktly bio- eheim substrat pro) and it is doing a fantastic job and its super quiet.
I also have an ac that probably about 10 or so years old and its still running like its new with great water turn over.
Good filter, but the only filters I have ever owned that lose siphon with a power outage even when the tank is full. Cost is great, but you get what you pay for. The cheap plastic cracks and breaks easily, the flow adjuster is annoying, and the media "tray" is really pointless for anything but the sponges. The price, sponges, and water turnover are what make this filter worth it though.
I love AC's. Easily the best HOB filter and I have had a few different brands. I like the ease/low cost of maintenance and the quietness. They move a lot of water, I think my AC 70 moves almost as much water as my PennPlax 300(which is supposed to handle up to 100 gallons, yeah right)
I do not like the brittle plastic as others have pointed out. You have to be gentle with them. Well worth the money IMO, I would not buy another brand of HOB filter.