Are you running just an air pump through your air stone or is that your CO2? If your running the air stone along side your CO2, you are basically getting nothing accomplished cuz your getting rid of all the CO2 you are trying to add to your tank. I would just take the air stone out or only run it at night.
I don't really have co2 but I must be doing something right because I have some new plants starting to come up. I'm not sure what they are yet but I was telling my wife "this is cool come check it out." I was pretty excited about it.
Little update: I have algae on my tanks glass and some on the little rocks in my tank. I been running the light 8hrs a day trying to see if that works but nope. The weather here got cold this week down to 30° and I had one glowlight die not sure what happen but it might of been old already. One of the bulbs I planted is growing like crazy one of the leaf's on it grew all the way out of the water and some new plant is growing too.
That is what I have on mine and I have separated in 2on 3 off and 3 on.
Just make sure you clean the existing algae very well change water to get rid of their spreading and after you set for 5hrs observe for at least 2 weeks to see if you are getting algae again.
Only change the light period time, so you know what you are observing is related to one isolated factor.