Assuming room temperature remains stable, the amount of yeast determines how
fast the sugar gets converted to CO2, or your BPM/BPS.
This graph, although it actually represents something entirely different (electronic musicians will recognize it), does a pretty good job of showing the production rate over time:
The DIY bottle enters the "release" phase when one of two things happens:
1) Sugar starts to run out.
2) The byproduct of fermentation, alcohol, starts reaching toxic levels for yeast.
Whichever comes first.
Adding more sugar extends the "sustain" phase and overall production time. But if you add too much, alcohol will cause it to enter the "release" phase before all the sugar is used, and the rest goes wasted. You can detect this by tasting the contents of the bottle when production sharply drops off, if it's still very sweet, you have too much sugar.
If the production time was otherwise acceptable, just reduce the amount of sugar, so that less is wasted. Or if you need more production time, add more water - this dilutes the alcohol and delays toxicity.
How much BPS (and therefore yeast) you actually need for your 10G high light tank depends on two things:
1) How the CO2 is dissolved in the water (methods vary in efficiency).
2) How fast it's being lost from the water due to surface agitation from filters/powerheads.
Neither of which you specified. Even if you had, there is still some guesswork involved, and that's where a drop checker that can measure the actual CO2 level in the water comes in very handy.
Assuming you have a HOB filter, I'd recommend starting with this recipe:
* 1.5 cups sugar
* 1/2 tsp. yeast
* 2L bottle filled with water, up to the point where the bottle starts to taper off
Your current 1/8 tsp. of yeast is certainly way too small. In fact, you probably need more than the 1/2 tsp. I recommended. But better to go slow than risk gassing fish. Keep an eye on them when the recipe starts producing and make sure they aren't stressed. If after a day you think they can tolerate more, you can always dump out the bottle and try again, adding 1/4 tsp. more yeast each time. Yeast and sugar are cheaper than fish.
Finally, the baking soda you added is kind of a fine adjustment, which can either help or hinder both stability and production time slightly, and it's not critical you add it for now.