Don't use plastic bottles to produce CO2 anymore!
Here’s a more professional, reliable, efficient generator for your plant better growing.
generator produces high pure CO2 based on acid-alkali reaction theory.
After whole reaction in bottle, low pressure will be output steadily by using of pressure reducing device.
CO2 will be output through fine adjusting valve and bubble device into diffuser for aquatic plants photosynthesis.
You can use the solenoid valve with a timer to synchronize with the light.
Also we have a manual version, you can search for it with keywords WuyouChy CO2 Generator.

It’s more safe and reliable that the bottle body adopts SUS304 stainless steel.
The measured burst pressure is more than 200kg/cm2, and the Safety Valve will open automatically when it is over the safe pressure.

It’s more professional and efficient because all accessories you need are included.
Tertiary Filter: prevent the reactants from overflowing and make the airflow clean
Pressure Reducing Valve: keep the airflow low pressure and steady
Pressure Gauge: for pressure observing
Safety Valve: open automatically when it is over the safe pressure
Fine Adjusting Valve: adjust the CO2 outlet speed
Bubble Device: for bubble counting and observing
Solenoid Valve: used with a timer to synchronize with the light.
Check Valve: prevent air or water flowing back
Diffuser: refine the bubbles and make it easy to dissolve in water and be absorbed by plants
[Note:] The Check Valve is optional. To install it, cut the tube and connect the valve between the two tubes. The black end of the Check Valve is the air inlet.
Recommended Reactant:
200g Citric Acid , 200g  Baking Soda , 300mL Water. (reactant not included)

one order Reaction  materials  Contains 200g Citric Acid , 200g Baking Soda