DIY CO2 system using Soda Stream bottles

[macquarium]

Hi all,
Having basically given up trying to find a place that will refill the small bottles most of the commercial CO2 systems come with (Aqua Medic, Dupla, etc), I've more or less decided that it's best if I build myself a system and use readily available Soda Stream bottles. If anyone else is doing them, I'd really like some advice.

Soda Stream bottle adaptor - not a problem, a guy on eBay is selling them for homebrew purposes.

Regulator - again, eBay has plenty that are designed for home brew, but are these suitable for aquarium use? One I've got my eye on is a Harris 601; it's dual gauge and the price is very reasonable. What kind of working pressure do you want to be sending to the needle valve?

Needle Valve - where do people recommend getting one of these in Australia? Welding shop? Is there anything in particular that's required for aquarium use (other than a very fine degree of control)?

Control Solenoid - eventually I want to get (or build) a pH controller and have an automated system... recommendations.

Just to thicken the plot... I've found a place selling the AZOO CO2 dual reg that has both a needle valve and solenoid built in... for $150. That sounds pretty darn good price-wise - anyone know if they're any good?

Cheers, Ben.

[Technics]

I have a soda stream bottle, adapter and regulator that's set up on a nano tank. There's no pH controller because I think you can do well enough without one(had one on another tank and stopped using it becuase I could get away without it). Once you have the adapter for the soda stream it's the same as using a proper bottle.

What size tank are you putting this on? I'm not sure of how good the economics of using these bottles on larger tanks would be. The gas is pretty expensive per KG purchased this way.

I have a needle valve and regulator from a welding supplier on another system. It doesn't really give as fine control as I'd like.

I've seen the regulator you mention. I haven't tried it but have been considering getting one.

[shake]

Hi Ben and weclome to Aquariumlife.

If you are looking for a needle valve check this place out.

http://www.swagelok.com/default.aspx?dcode=NMELB

They use to carry a good range of needle valves. Many people in Oz and the States have bought from them.

I personally have not bought from them, but reading other forums, this comapny always gets mentioned for needle valves.

[nornicle]

soda stream bottle (cheap)
regulator $38 ($32.50 online)
airline tubing (old and free)
dupla bubble counter $40 (i think)
cheapy pollen diffuser $10 - $XXX however much you want to spend on these things
CO2 permanent test $15

instant pressurised co2

btw how long does a soda stream bottle last for and how can you tell when its empty?

[rahmad]

[IMG]
btw how long does a soda stream bottle last for and how can you tell when its empty?

I believe that's why you need the pressure gauges. that way you can see how much is left before it bottoms out and you end up with a tank full of aquarium water.

I have always wanted to know where you guys fill up the bottles. I have been told that homebrew places tend to be more forgiving than BOC.

(as an aside who pronounces BOC as separate letters or one word?: "B O C" or "boc")

I have a shop here selling the sera basis co2 setup for $450. for my 90L tank that should last me ages apparently. any ideas guys?

[Grubs]

nornicle - your $38 regulator looks more like a needle-valve (aka metering valve) rather than a pressure regulator.

A true pressure regulator has a diphragm inside and looking at yours there doesnt seem to be space for one. Normally you'd have at least one guage to tell you the pressure you are regulating the lines to... or if it doesnt have a guage they tend to be set at a fixed pressure like on a gas BBQ.

Without a [pressure] regulator your bubble rate will slow down as the bottle pressure drops (this may not matter if the CO2 gas holds a fairly constant pressure in the bottle until the liquid has been used up?)

how can you tell when its empty?

.. the bubbles stop?

[nornicle]

I have a shop here selling the sera basis co2 setup for $450. for my 90L tank that should last me ages apparently. any ideas guys?

bring to coles and ask the service desk to swap over for a new one.. $10 or something..

[nornicle]

Without a [pressure] regulator your bubble rate will slow down as the bottle pressure drops (this may not matter if the CO2 gas holds a fairly constant pressure in the bottle until the liquid has been used up?)

.. the bubbles stop?

youre kind of right

it's basically a way of manually adjusting the output of gas.. it doesn't account for the output of the gas at an exact level.. given that its going on a small tank and i monitor it daily for bubble count and its not on an automatic dosing system..

So it works for me

as long as it doesn't dump its guts when its empty which im almost 100% certain sodastream bottles dont...

[holotype]

how can you tell when its empty?

Weigh the bottle when it is empty and make a note of it.

[Technics]

...or when it's full. The weight of the gas is specified so you'll know when it's almost done. It would be a good idea to have two of the cylinders.

[macquarium]

What size tank are you putting this on? I'm not sure of how good the economics of using these bottles on larger tanks would be. The gas is pretty expensive per KG purchased this way.

Sorry I did reply to this yesterday but by the look of things it didn't work :-(

The tank is... a MacQuarium (see here -> http://macquarium.takebacktheworld.net/)... so I'm guessing if you'd probably call it a pico tank - it's capacity is about 10L. Previous efforts have used fermentation-style CO2 injection, which works great when the tank is being grown-in without fish, but because of the lack of control I'd always remove the CO2 once the plants had grown into the desired size and shape and the fish were added. This saved the fish from wild pH fluctuations when the yeast started running out or going to sleep, but for most of the plants resulted in stunted rather than slowed growth. Basically they'd just slowly fade.

This time around, because I want to try my hand at some more demanding plants, I'll to use pressurised CO2; once the grow-in period is complete I'll regulate the gas to around 6-10ppm to keep the plants growing and happy - and hopefully still saturating the water with O2 - but at a reduced rate so I don't have to prune every other day. Fast growth can choke a small tank like this really fast!

You're right about the sodastream bottles' value for money, but because nowhere here can supply or fill the small (under 1KG) bottles, it's either them or a big BOC cylinder. My CO2 usage will be low, probably one bubble every 5-10 seconds after grow-in, plus I really don't have the room to have a D size cylinder in my office (not to mention what my other half would think of its detrimental aesthetic to our house ;-) ).

And the BOC cylinders aren't cheap either - about $10 a month plus I think $40 for a refill... I can get two new 40L sodastream bottles for under $80, and each refill costs $11... and the hardware store is at the bottom of our street. Obviously with a bigger tank the economics slide towards big cylinders, but in my case, SodaStream will hopefully be fine.

Having read some good reports on the AZOO reg/solenoid/needle valve, I'm going to go ahead and order it and start moving on the project. I will update everyone when there's something more to show.

Thanks to everyone for their help!

[nornicle]

100litre, how many grams is that?

the 40l is 330 grams and i thought it was abit small.. the 100 litre... that could work on bigger tank for months at a time..?

[Grubs]

macquarium that looks great. I suspect a single soda stream bottle will last you a very long time indeed in a tank like that!

You might also want to ask pleco4me about his kit 4 sale if it uses the little CO2 soda bulbs it would be economical for your tiny tank (I couldnt quite work out what the supply was on the hydor kit).

[Technics]

Agreed. I think Soda Stream cylinders are great for tanks of this size and it's easy to get the refills. There are some disposable cartridge systems I've seen and I'd say they would work out a lot more expensive. My SS is on a 15L nano. I have a 3.5KG CO2 fire extinguisher on the larger tank.

[shelleygirl]

I've always been interested in the sodastream setups but was never quite sure how to put it together. Wondering if you guys could post step by step guide on how to DIY sodastream.
Also are sodastream setups only suited for tanks under 100litres? How long do your cylinders last for?