Co2 and airstone-will they cancel eachother out?

The air stone will lower the co2 levels. You could probably just turn down the co2 a little bit...

I would if the drop checker was more green. I understand it should be a lime-green if Co2 was at good levels for the plants? Right now I would actually like more Co2 in the water, but my Angelfish don't seem to like it.

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.

Hmm, ok. I'll try changing the solution in the drop checker and see if it isn't just old-does it get old?
I am trying to get rid of algae right now, so that's why I think it needs more Co2. after adding the second Hagen the algae growth seems to have slowed, but not stopped. And my plants are not growing as fast as i think they should be, but i am no expert
You are right though, if my fish are having problems then I need to find another solution.
I just find it odd that only the Angelfish seem to be having problems, everyone else is hunky-dory.

And I don't ever get pearling. Lucky you, and good job!!

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.

I am EI dosing, so I have macros, csm+b and iron. Mon, wed, fri I do macros (1/4tsp for Kno3 and 1/16 for the other two) and tues, thurs, sat I do csm+b and iron (1/16tsp for both) 29 gallon tall tank, two 24w T5Ho bulbs, about 3 inches off of tank surface.
Thanks for helping me!

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

if you run an airstone, the co2 will off-gas faster, and you will have lower levels. But you will also have higher oxygen levels, which are important for the fish. If you add an airstone, and increas the amount of co2 you dose, then you can have high oxygen levels, and high co2 levels which will keep plants and fish happy.