That "bio generator" is just a manufactured DIY CO2 setup. It uses sugar and yeast to make the tiny bit of CO2 we need for injecting into our aquariums. But, it is barely able to provide an adequate supply for a 10 gallon tank, so there is very little chance of getting too much with a bigger tank.
The pH drop that CO2 causes, because part of the CO2 goes to making carbonic acid in the water, does not affect either the fish or the plants. In fact pH is not an important variable for fish. In a fish only tank, no plants, the pH can be seen as an indicator that something else is wrong with the water, so an out of limits pH would be a bad thing. In a planted tank, with the plants consuming nitrates, phosphates, ammonia, and emitting oxygen, and CO2, at night, the pH varies according to what the mix of various compounds is in the water.
A high pH will usually mean a high KH, and high KH can be a problem for some fish, but the pH isn't. So, don't be concerned about the CO2 caused pH changes.