I took all the gravel out of my fish tank and washed it, then i wiped the glass, and did a 20% water change, since then i have lost a pleco and platy, and the rest of the fish, which are: white skirt tetra x2, danios x2, red eyed tetra x2, pleco x1, and platys x3, and tiger barbs x3 are swimming on the surface as if gasping for breath, i considered getting a straw and blowing bubbles in the tank - is this a good idea?....i am so worried, and want to help them,but what can i do? I don't want any-more to die - i only washed the gravel and wiped the glass, i didnt wash ornaments or anything and i have two lots of real plants for oxygen in there. They wont even eat.