Hi Guys! I need help! i didnt know where to post this thread so i hope its ok here, When i got home this morning i noticed about 25% of my fish gulping for air at the top of the tank! i have a planted 6ft tank established, with convicts, severums, tigerbarbs, and a keyhole. I have two tanks at the moment one 30 gal with 5 juvenile green terrors. I think that the 6ft tank isnt getting enough oxygen! but i only have 1 airation stone between the two! so my question is! why are my boys at the top of the tank gulping for air! will a water change help?! i performed one not two days ago 25% Amonia - 0 nitrite 0.50 nitrate 10ppm, i added new plants yesterday, im worried that my guys are dying I just put the airaition stone in the 6ft so how long will it take to fully oxygenate the water?!