The discussion has continued on my club's list and one of our members is opening a specialty plant shop and some people from the club are buying these directly from him and one of the customers received this from him. This is a direct quote from the manufacturer.
1. You will need two 2 liter PET soda bottle, e.g. Coke, Pepsi, etc.
2. Mark these bottles as Bottle A and B.
3. Empty Reagent A (Citric Acide 200 grams) into Bottle A and add
600ml of water. Shake well until everything is dissolved. You will
notice that the water will be colder to touch.
4. Take out one of the DIY CO2 system. There are two areas where you
can screw on the PET bottles. The first one is the one with a
pressure gauge (A) and the second one is the one with the regulator
5. Screw in Bottle A you made in number 3 into DIY CO2 (A).
6. Empty Reagent B (Baking Soda 200 grams) into Bottle B and add
200ml of water. You do no have to dissolve the contents in Bottle B.
7. Screw in Bottle B into DIY CO2 (B).
8. Close the regulator of the DIY CO2 and make sure it is completely shut off.
9. Squeeze Bottle A until liquid in Bottle A starts to transfer to
Bottle B. You should see reaction that will start producing CO2.
Keep on squeezing Bottle A until bottle is very firm (full of gas) and
you can't squeeze the bottle anymore.
10. Attach CO2 gas tubing to the regulator and to the CO2 diffuser.
Release regulator slowly until you see bubbles coming out of the CO2
Many first time users turn on the regulator too fast resulting to the
citric acid water moving too fast to the baking soda area, thus
reducing the true potential lifetime of the co2 production. The whole
trick here is to trickle drip citric acid into the baking soda bottle.
You don't have to touch anything for the citric acid to flow into the
baking soda. Once reaction started, it will automatically such citric
acid into the baking soda when it is needed. However, it has been
observed that you may need to swirl the bottles once a week to make
sure that fresh baking soda gets exposed to the citric acid.
You should get around 6 weeks at 8 hours a day of CO2 at 1 bubble per
second. Although we can get sometimes up to 8 weeks.
So if you read till the end they state that it should be shut off daily, manually I don't do that currently but will be investing in a solenoid to do it for me lol.
Like stated above the pressure can not increase with it shut off if it is up to working pressure, the pressure inside of the bottles is what causes the whole thing to work and causes a syphon to build up more pressure when it is needed and only when it is needed, kind of genius once you get how it all works. It's really hard to explain it without seeing it work in person.
Eheim Pimp #232 Nikon Pimp #69