CO2 Question

Hi! I am thinking about adding DIY CO2 via the yeast method. I am concerned however on the effects this will have on an already established tank. My tank is mostly a plant tank (Apon longifolius, Crypt wendtii red, Ludwigia repens, Anacharis Canadensis, Sagitteria subulata forma filiformis, Valisneria spiralis, Alternanthera reineckii, Anubias species, Ceratophyllum demersum, Hygrophilia difformis, Hygrophilia polysperma tropical sunset, Liliaeopsis, Vesicularia dubyana, and a light green colored plant with small pointed leaves that is growing like mad but is yet unidentified) however I do have a few fish I have grown rather attached to.

I have a pair of red flame dwarf gouramis, an albino pearlscale angelfish and 3 kuhli loaches, plus an army of otocinclus. I am concerned that the pH swings will affect my plants and fish adversely. Any thoughts would be appreciated.