Best Media Reactor
1) I have used Two Little Fish reactors in the past but they are garbage, the fittings always leak, inserting the media w/o getting any in that center tube is near impossible. The sponges always clog prematurely, and sometimes the lids fail too.
2) I then went to the NextReef media reactors which were nice but again they use that center tube, and the thumb screws are a pain.
3) Then I went with the Reef Octopus which I loved, screw on lids no more thumb screws, came with silicone tubing for the pump, and a nice ball valve to control flow, thick clear acrylic, the only thing is just a little pricey.
4) BRS reactors are great for the price, hold a lot of media, thick acrylic easy maintenance just screw off and the media holder drains into the outer cylinder so no mess, easy to dump out and refill w/media because no center tube, any small pump is all you need to run since they already come with a ball valve to dial in, low price probably the best reactor for the money. I would avoid the dual, you'll never get that one dialed just right and you'll end up either over tumbling and pulverizing the GFO or carbon.
Hope this review of what I've owned and operated helps you with your choice.