Currently after much evaluation of Dupla's and a host of other commercial brand of CO2 setup, they are either overpriced or of inferior quality. So I decided to put my creative talent to good use by building a Hi-tech CO2 setup myself. I use a semi-automated CO2 injection system that I put together to provide the proper levels of CO2 for optimum plant growth and stable pH in my plant tank. The CO2 system is fed from a 5 litre CO2 bottle with a commercial two stage regulator, thru a solenoid valve and fine control needle valve into the bubble counter before being discharged by a CO2 reactor. All available from local Singapore sources. Here is what is recommended you should get:
CO2 cylinder & Solenoid valveI got mine from a commercial gas company, it carries all kind of cylinders. Like I mentioned, a 5 litre one will do and it will definately outlast any of the range of CO2 bottles carried by Aquarium supplier. A simple reason is that they want you to go back and refill all the time, more business. But as for a single 5 litre refill, it will probably last you a good 9 months if the bubble goes at a rate of 1 bubble per second. The place where you buy the tank should be able to refill it. Get a 5 litre CO2 tank from : Sing Swee Bee Enterprise Pte Ltd Tel : 7527892 * Important thing here when getting a refill, ask for the type of CO2 that is food grade suitable for human consumption. Most of the aquarium shop don't even know the difference between a food grade CO2 and an industrial grade CO2 (which is useless for Aquaria, industrial grade CO2 feeds all kind of mixed gas besides the C02 that bubble into the atmosphere and poison your fish and plant, not excluding yourself! hehehe:)
RegulatorNext thing you will definately need is a regulator, the place you bought the gas tank from also sells regulator. The best is a two-stage regulator designed for use on welding gas cylinders. This reduces the 950 psi tank pressure to 10-20 psi. The regulator has high and low pressure gauges and a control to set the low pressure. I set the low pressure to be between 2 and 4 psi to allow fine adjustments of the actual flow. You can get a high quality stainless steel twin gauge one that beats all the commercial ones sold by the aquarium shop hands down! And the beauty of it, you pay less for more, for just about S$70.00 dollars, it is a lifetime investment that won't break down. I paid $70 for an adjustable regulator with high and low pressure gauges. The high pressure gauge tells you when the bottle is about empty. The bottle pressure will stay at 950 psi as long as there is liquid CO2 in the bottle. Once the liquid is gone, the pressure will begin to drop. When the pressure is around 200 psi, you should recharge the bottle since the regulator gets a little flaky at that point. You can also get the regulator from the same company : Sing Swee Bee Enterprise Pte Ltd
Solenoid controllerFor automated time release of CO2 is a solenoid device capable of controlling up to 100 psi. My solenoid is controlled by a light timer set on regular interval. It can also be controlled by a electronic pH controller if you want to get fancy. I found a commercial unit for about S$60. It's definitely over-kill but it has never broken (Made in USA, damn good stuff!). It's good for 200 psi and it's non-corrosive. You can get it from : Beaver Contromatic Tel : 7469677 Model : 21A2kV30 Type : 240 VDC Cost : S$60.00 The solenoid goes after the regulator on a CO2 cylinder, i.e. the low pressure side. Some solenoids use the inlet pressure to help keep them off and may not work in this application. The regulator usually has a 3/8" NPT thread and the solenoid may have a 1/4" or 1/8" NPT thread, so you will need to find a place that sells step up and down thread adapters. Most good hardware stores and plumbing supply places have these. I found a good source where you can get all sorts of valve and adapter, at a company called : Singapore Valves & Fitting
Fine adjustment controlAfter the regulator, you will need a fine control valve to regulate the flow to get the extremely slow flow rate you need (1 bubble per second for a manual setup). I have a Nupro needle valve to provide the final flow adjustment into the reactor. With the low pressure, the valve can easily be set to a flow of 1 bubble every 10 seconds. Initially, we have it set for 1 bubble every 1.5 seconds. It is a pretty Hi tech stuff for industrial use which you could get for $60. Typical aquarium needle valves won't work - you will find they are either all on or all off in this application. I have one by NuPro (model B-4MG2) that cost S$60.85 and is superb, state of the art stuff. Another worth-every-penny-investment. You can get it from : Singapore Valve & fitting Pte Ltd Tel : 3670688 Model : B-SS4-A/ Nupro Fine metering valve Type : Brass Cost : S$60.85
Bubble counterTo help set the flow you would need a "bubble counter" to provide a visual indication of the actual CO2 flow. You can inject directly into the tank or you can see how much is going into the reactor, this is optional. I made a homemade Bubble Counter (from a mini baby milk bottle which you can buy it for less than $3, comes with a silicone nipple on the inner cap) I drilled 2 holes top and bottom and fit in a single 1/8" plastic valve you can get at any aquarium shop for S$0.15 and silicone it to seal off the gaps, fill it up 3/4 with water and that's it, a bubble counter. The cost of it, for less than $4 bucks and I provide a check valve to prevent water from backing up into the solenoid and regulator (something to be avoided!).
Silicone tubeI was ripped off when I bought some silicone tube. I went to "Aquatechnique" and the salesman sold me 3 metres of silicone tubing by Dupla for $7.50 ! and later I found out that I could get it for $0.50 per metre at the local aquarium that carry silicone tube! I have a three-millimeter or 1/8 inch thick silicone tubing that is used to connect the bubble counter to the valve and reactor. The bubble counter is mounted on the front of the trickle filter so it is easy to monitor.
CO2 ReactorIt doesn't have to cost you an arm and a leg to build a reactor and the last thing you would want is to get a dupla reactor from Aquatechnic, it cost a mini fortune. Anyway, lots of dump folks got ripped off by them. I built my reactor fashioned out of a 200ml baby milk bottle which uses a very high grade polycarbonate plastic. It works great as it comes with a silicone nipple which can act as a watertight seal. Drill 2 holes on the top and bottom and glue in a single plastic gang valve from the bottom for the silicone inlet tube. the top one is fitted with an elbow adaptor that goes into my canister filter. The CO2 gets pretty much chopped up by the time the water enters into my tank. Throw in a couple of mini bioballs into the cylinder and voila! you have a reactor for less than $12 bucks! You can use your imagination to design all kind of reactors that will work for a song, only if you put in some time.
So here's a rundown of the parts and cost of my typical CO2 system:5 litre CO2 Tank - S$85.00 CO2 regulator - $75.00 Both bought at : Sing Swee Bee Enterprise Pte Ltd Tel : 7527892 Solenoid controller - $60.00 Beaver Contromatic Tel : 7469677 Model : 21A2kV30 Type : 240 VDC Cost : S$60.00 Nupro 'S' series metering valve (needle valve) From : Singapore Valve & fitting Pte Ltd Tel : 3670688 Model : B-SS4-A/ Nupro Fine metering valve Type : Brass Cost : S$60.85 CO2-approved airline tubing - silicone ones are also good. Don't use cheap aquarium airline hoses, they may become brittle and leak under long-term CO2 exposure. 3m - $1.50 Available at all aquarium shop
Total cost for a Hi-tech CO2 injection : SGD$282.35Not too bad for a hi-tech CO2 injection system if you look at long term cost of less than $5/- per month if you use it for 5 years. Really worth the hassle! You don't have to be rich to be clever - Ikea
James Lim (firstname.lastname@example.org)