It depends on how much agitation is going on in that sump. Its there is a wer/dry in there then virtually none will get to the display tank. If its bio balls or similar, you will lose some but probably not enough to worry about.
You can measure your ph and kh and infer your dissolved co2 levels ( search it cuz it involves a chart and ive never done it). But the main thing is watch the plants. If they grow better then your good. But if this is your first planted tank or co2 excursion then obviously you dont have a reference. Tell me some of your plants and lighting and i can give you a ball park on how fast they should grow
Edit: size of the tank is important too, what ya got
Edit 2: id drop the yeast and go with citric acid and baking soda. You can get twice as much co2 for the same or less price. Some chemistry major did a balanced equation proving the yield on citric is much higher
Last edited by fish jihad; 01-26-2015 at 12:02 AM.
Reason: additional info