The latest fishkeeping products reviewed, including a CO2 diffuser set from Colombo and a Vultron airpump. Plus a look at three brands of polymer balls – are these spheres the future when it comes to maturing your pond?
Price: Sold separately – Co2 profi Set sells for between £150-£200, Solenoid around £65 more info: www.colombo.nl Reviewer: nathan hill
In a market that was for a long while saturated with expensive entry level CO2 diffusers, many of us lost confidence in the idea of affordable carbon for the aquascaping hobbyist. Some of us took the risky high road of using CO2 fire extinguishers to make things economical, willing to offset the chance of a regulator failure against forking out astronomical prices for aquariumdesignated cylinders of gas. Others persevered with off-the-shelf designs and rapidly realised how costly it became.
This Colombo offering sits somewhere in the middle. It’s pretty pricey, but arguably much safer than a fire extinguisher. To its benefit, it has a cylinder that holds 800g of carbon dioxide – many of its nano rivals have cartridges (too small to even call them a cylinder) as little as 20g.
You can assess the efficiency of that for yourself. For 20g cartridges you’ll pay out somewhere between £10 and £18 for three of them – 60g total. A refill for the 800g Colombo set comes in around £40. But then again, I typically pay around £25 for 2kg of CO2 in a refurbished fire extinguisher. 800g will supply me enough gas for about two or three weeks at best in a 60x30x45cm aquascape, assuming I’m not gassing heavily.
The regulator itself is weighty, sturdy and has a smooth enough action. With CO2 dosing you want really fine tuning abilities, and
this has it. Whether you want one bubble of gas every second, second-and-a-half or two seconds, you can do it with accuracy. It connects directly to the top of the cylinder through a thread action, and as long as you keep the threads absolutely clean (I’d frequently go over my regulator/cylinder threads with a cotton bud and some silicone lubricant), then you won’t experience gas leakage. If it’s the first time you’ve ever connected a regulator to a cylinder, I’d advise being quick, otherwise a little blast of released gas can give you a sudden ‘hand chill’.
Also in the package you get a length of CO2 resistant tubing and a bubble counter/diffuser. Depending on how hard your water is, that tubing will eventually turn a chalky white and go brittle, so I suggest replacing it every few months (but if you’re an aquascaper obsessed with everything looking fresh, you’ll likely do that anyway). The bubble counter and diffuser positions in the tank easily enough, held in place with a sucker (again, get a couple of spares as this will turn chalky after a while), while opening it up to clean it just involves unscrewing the head and getting inside. Look closely and you’ll see a little spring in there as well. That’s the non-return valve that means if you ever run out of gas, the water won’t start syphoning back out of the tank.
That’s the whole package. I won’t lie, it doesn’t seem ‘that’ great value, especially if paying near the £200 kit price. With £40 for the cylinder, that means I’m paying out £160 for a regulator, some silicone airline and a bubble counter. I don’t even get any cheap clamps and suckers to tidy up the airline.
You can build on the kit by adding a separately sold solenoid. When plugged into a timed socket (around £3 upwards from electrical and homeware stores), this allows total on/off control of your gas supply. The usual ‘scaper trick is to turn the gas on an hour before the lights come on, and have it lead by an hour when the lights go off again. This avoids huge swings of ph, as well as wasted CO2 (since plants don’t use it at night).
My worry is that the solenoid is in-line. I’ve tried to butcher something like this together in the past on a pressurised CO2 unit, and all that happened was that the hose exploded in the night. Perhaps I was using substandard hose – or perhaps Colombo knows something that I don’t. Either way we couldn’t put it to the test as the solenoid didn’t work when we plugged it in, and we’ve given up on waiting for the replacement to come through.
They aren’t cheap, they aren’t easy to set up and are risky when set up wrong, but C02 really helps plant growth.