snails co2?

Do snails release co2 like fish do??? And is there always some co2 in the water no matter what??

Don't know about snails releasing co2 but I would think they would...

I would think that there would always be co2 in the water but depending on aeration / off gassing it could drip to almost nothing.
From the reading I have done, in an aquarium setting normal co2 levels sit at 5ppm and that fish or other inhabitants don't really put off enough to count for anything.

Then you add air stones or HOB filters mixing the water surface and that could dip even lower. This is why those who inject co2 for plants attempt to have a placid water surface.

That all sounds like sound logic.

yup^