Elos Set 300 CO2 kit review


Nathan Hill takes a look at a top-end piece of CO2 equipment that's a real treat for the precision aquascaper.

Top-end aquascaping gear has come dangerously close to being a one-trick pony in the UK, with one company dominating the title of the 'premium' equipment manufacturer. Hopefully, that’s all about to change with European company Elos at last dipping its toe into British waters.

The Elos Set 300 CO2 is for aquaria of up to 300 l/66 gal (pending KH values). It includes a gas regulator and valves, check valve and CO2 silicone tubing, and a permanent gas checker. Most of all it contains some of the most exquisite blown glassware around — in the form of the drop checker, bubble counter and diffusing reactor.

Designed to be run with a separate pump, or more practically in tandem with a canister filter, the diffuser has a long contact method of gas to water that doesn’t involve the usual spiral design. Rather, there’s a sort of convergent/divergent flow involving tubes within tubes in a way that shouldn’t be obstructive to clean should the need arise.

Vented gas

The idea is that water flows into the top of the reactor/diffuser at the top, where it will mix, Venturi fashion, with the passing water. Any excess pressure that builds up within the chamber is vented off via an exhaust.

The piece can be mounted onto glass with suction cups, or, if preferred, can be free hanging if used with a separate pump.

Given my penchant for breaking glassware, my choice is for the former, although the latter would admittedly look a little different and very smart.

The bubble counter is similar to many now seen and nicely complements the reactor in the tank, as does the drop checker, in an unusual, 'inverted lightbulb' design. My only concern is the fragility of glass when rummaging in or cleaning an aquarium.

The valve is solid, heavy and dapper. It lacks dials or indicators regarding pressure and remaining gas content that seem to be standard on many other kits — but what it lacks it makes up for in sheer aesthetics and accuracy.

With a slow action, it offers a precise dispersal of gas, which many kits seem to overlook. After all, getting the right amount of gas into the tank is rather the point of injection…

Out of the box it is compatible with fire extinguisher adaptations, although I suspect that with the use of the correct Allen key it can be reduced further to also accommodate small disposable CO2 canisters.

The 300 set also lacks a solenoid, but for someone like myself who likes to fiddle with my CO2 kit every ten minutes this is no issue. Planted tank keepers seeking the easy life might find this something of a loss, however. Saying that, there’s the option to add one later.

Strength of packaging should be applauded and I suspect the box could withstand several natural disasters and vehicle crashes before the contents broke.

The biggest issue for anyone wanting this kit is actually getting hold of one. I had to chase around for some time until I eventually found Fish Antics stocked Elos in Ireland, with Peter Moon distributing for the UK — and even then it had to be ordered in for me. It was eventually handed over in person by Portuguese aquascape legend Filipe Oliviera at a trade show.

This is a top end piece of CO2 equipment, with a price tag to match, but will be something that may tempt those who already have their eye on an exclusive glassware kit for their aquascape.

Currently, this is something that will need to be ordered especially, so don’t expect to see many about.

Price: RRP £369.95

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