BBradBury: So when i do a water change its around 50%. most likely a little less. I have to do the CO2 or my steam plants just melt away. The agitation at the surface could be alot better, but my mom complains and says its too noisy when i try to fix it. It was a losing battle so gave up on that. SO the only thing really agitating the surface is the air bubles
MArland Guppy: As for temperature i tend to have it on the higher range around 78-80. 80 rarely.
Waterlife, you may be right cause i try to put a little higher than normal on the ferts when i put them in during a water change. I dont get alot of time, most of the time none at all, during the week to work on the tank during the week. AS for hardness and pH i have hard water like really hard and my pH is around 7-7.5. I have tested the pH before when i had this problem, as in affter i put it in, and didnt notice a large change
BruceF: My water change procedure; remove the old water, get new and place the the ferts in the new water, and there liquid.
And as for o2 being my problem, its just a hypothesis. It may not be very soundd cause not all the fish are afffected by whats happening, the small fish are fine and the plecos and cat fish do not seem to be bothered by it. And i agreed with you on it being higher, i know water chemistry can get crazy, and im a geologist not a chemist, but i do know certain things can affect the amount of oxygen in the water column, so thats really what in going off of