New DIY co2 system

[charlie]

Myself & some other members recently saw a demo of this twist on the old sugar & yeast DIY CO2, from all appearances it looks way better than the DIY Sugar & yeast. This kit consist of caps , valves ,  pressure relief valve, gauges, needle valve.
The mixture is citric  and baking soda as the base & is touted to last 8 weeks, I know angelfins.ca is carrying it
http://www.ebay.com/itm/New-Updated-Version-Complete-DIY-CO2-system-Kit-planted-marine-aquarium-/170968599404
Regards

[exv152]

I think this is a great alternative to the yeast which last only 2-3 weeks. One down side I see is that it will create co2 in burst, as opposed to a steady supply.

[ma_clement]

I don't understand why we would need the kit...?

Can one just use silicon stick together the tubing and the regular bottle caps?

[charlie]

This.methid produces more pressure & also morre consistent pressure.
The way it works is through negative pressure , when the pressure drops in the first bottle the acid is drawn drawn from the second bottle to generate more co 2.
The kit offers better sealing & output control via  the valve shown in the link
The demo we saw also showed a pressure relief valve.
Regrads

[pm]

I know I am revising an old thread, but I have recently tried this method of DIY co2, and it has worked well for me.... significantly better than the yeast method.  I didn't buy one of the ebay contraptions and just did everything DIY using stuff I had around.
 
My setup doesn't need high pressure, so I don't ramp it up to high, I keep the pressure low.  The system works on pressure differentials between the two bottles.  As long as there is a little built up pressure, it works great, sucking acid into the baking soda as pressure in the baking soda bottle decreases (by use).  The 1 bubble per second I am using slowly causes the acid to flow into the baking soda.  As the two react, the increase in pressure pushes the acid back into its own bottle, where it stays until the pressure changes again.  There are no big reactions, just small ones of perhaps a few CCs each time.

The key in my opinion is the "Y" connector tube in the baking soda bottle.  This allows air (co2 actually) to push the acid back into its bottle, keeping the two solutions apart. If there wasn't a way for air to do this, I assume the baking soda solution would be pushed into the acid bottle... now that would be BAD.

I am only using an airline valve to control the bubble rate, but it still works great.  The rate is constant, instant, controllable, and can be shut off at night.

This is just a quick review, and by no means would I say this system is risk free.  If anyone decides to try it, please research it first to prevent any mishaps.

[Pyrrolin]

I have used one of the ebay ones on a 20 long, for the price it is good if you can't afford a proper system.  A huge tip, freshco is the cheapest place to buy citric acid, It is 200 grams for about 1.49

[pm]

...freshco is the cheapest place to buy citric acid, It is 200 grams for about 1.49

Thanks for the tip.  I think the only other place I have seen it (in quantity) is in u-brew beer places.