[2in10]

If your fish don't like it then you have enough. As long as the plants are growing and you are not having algae issues then all is good. Have your filter return disrupt the water surface and you will be able to add more CO2 if you like.

I couldn't get my drop checker to lime green with out running at an almost constant flow with the CO2. My plants grow great and I get light pearling after about 2 hours with the CO2 on and my checker barely gets to medium green.

 

[2in10]

Yes it gets old and your fish may splash tank water in the checker that can affect the fluid.

What is your dose regimen? If you aren't dosing enough ferts you will keep fighting algae.

Running a bubbler or disturbing the surface will get more O2 into the water. Your CO2 usage will go up a little.

 

[2in10]

Lift those bulbs another 6" to 9" above the surface and see if that helps. Also manually remove as much algae as you can.