d.i.y. co2 injection

so, i have a fair few plants in the aquarium now and after reading other peoples aquarium blogs, it seems a cheap way of getting plants to flourish is to get more carbon dioxide into the water. thus reducing the amount of energy and effort the plants need to expend in order to assimilate the co2.

you can spend a fortune on co2 cannisters, injection systems, reactors and diffusers if you choose, or you can do what i have just done and make your own. basically as follows. one empty 2 litre coke bottle, tube into another smaller bottle, then tube out of that into the power head where the water is returned into the tank. plus arildite. then, filled the 2 litre bottle just less than half full of warm water(so i can lie it on a shelf hidden away). added to this 1+1/2 cups of sugar and mix lots. then add mixture of acivated yeast - 1/2 tsp mixed vigorously in a little warm water. re-assemble, et voila! it took about 2 hours for co2 to start being produced. i tested it with an airstone initially to see if any gas was being emitted, which is was so job done!

a word of warning for anyone who wants to do this. i have added safety features to the d.i.y. kit including a valve which will blow off if the pressure is too much, rather this than a room coated in smelly brown yeast mixture! and finally, co2 is produced faster during the day when it is warmer - which is fine as this is when plants do their photosynthesis and use up the co2. in the evening co2 is still produced but at a slower rate. i need to monitor the effect this is going to have on the pH, co2 + water = carboic acid, not sure if this reaction will take place i need to research but i have read plenty which tells me the pH will be effected and that it will also flucuate between night and day. i don't think i need to worry so much as it is only a small amount of co2 going into the tank but it will be interesting to note nonetheless. don't worry about the fish, they like it a bit acidic - until i started this experiment my pH hovered around the 6.4 mark.