RK2 is a company that is synonymous with commercial sized aquarium life support equipment, especially big honkin’ protein skimmers. You’re more likely to see a 12 foot RK2 skimmer running behind the scenes of your local public aquarium but in recent years, RK2 has been hard at work shrinking their technology for ‘smaller’ saltwater aquariums.
The XFLO line of small venturi powered protein skimmers have enjoyed a small but vocal following in the reefing hobby but an interesting larger model called the 5-AC has recently caught our attention. Besides their stringent adherence to strict foam fractionating principles, the big differentiating feature between RK2 skimmers and virtually all others in the hobbyist aquarium market is their use of true venturi valves to inject air, instead of the ubiquitous needle wheel.
RK2 definitely turned plenty of heads at MACNA 2019 by mating up this medium sized 5-AC skimmer with a beloved and recognizable Ecotech Marine Vectra L2 water pump, making this one of the first Ecotech Marine protein skimmers on the market. The combination of high volume and substantial pressure capability of the Vectra L2 is a great match for the Mazzei venturi used to inject air into the RK-2 5-AC but one thing that’s really piqued our interest is the performance rating RK2 has bestowed upon this beast of a skimmer.
Sure this skimmer seems pricy with an estimated retail cost of $2200 but it’s rated for between 1,000 and 2,000 gallons and you might be able to bundle the RK2 5-AC with a Vectra L2 for around $2500. Although this skimmer certainly isn’t about to fit under anyone’s tank, compare that to any of the ‘premium’ acrylic cone skimmers with fancy needle wheel pumps that can easily reach $2000 to $3000 for what seems like a lot less material and much smaller volume for fractionation to actually occur.
We had some very nice, extended conversations with the reps from RK2 and it’s about time we revisited venturi injected protein skimmers, both to highlight where they excel, and to frame the applications where needle wheel designs are still a better value or simply more practical. Seeing the RK2 5-AC running on a familiar pump like the Vectra L2 certainly helps makes us feel more comfortable about considering these ‘medium’ sized protein skimmers from a commercial aquarium life support brand. [RK2]