Planted Tank Guru
Join Date: Feb 2010
Location: Newbury Park, CA
Very nice tank! Are the bubbles on the right hand side CO2? This is a big tank for a simple diffuser if so.
I want the water to be at its lowest pH point when lights go on so there is lots of CO2 for the plants to use right away. The drop checker responds too slowly to see this. I took pH measurements when lights go on instead and ignore the drop checker. Half an hour after the CO2 is turned off at night the pH goes right back down but the drop checker won't show that level for several hours.
I suggest taking the water's pH when you see your drop checker turning that light green color as that is likely the lowest pH your water will have. Next day when lights go on check the pH again, if it is the same as the first test you are good to go. If not turn the CO2 on half an hour earlier until it is that pH when lights go on. Can do the same for lights out, see when the pH starts to rise and turn the CO2 off at that point.
Leave the drop checker in the tank and if it doesn't turn light green you know something is up, the CO2 tank is empty, there is a leak somewhere, there is a kink in the line........
You can leave the CO2 on 24 hours a day if you like but you should get more time out of each tank of CO2 if it is turned off 16 hours a day, only makes sense. If you are using a single stage regulator that can do the dreaded end of tank dump and if that dump happens when lights are off you could wake up to a tank of dead fish, shrimp and snails too. I have noticed this dump happening and turned down the stream of bubbles when it happens during lights on.