[supaflyz]

Today I went with my mom to go shopping. The fish were doing fine before I left. We only went about 2 hours then came home. I turn the aquarium light on and was about to feed them. I was really surprise the cardinal tetras all gather up to the surface and wanted to eat. They never done this before because they always stay on the ground and eat the left over from the discus. Today even the shrimp were jumping like crazy on the driftwood. Then I notice they werent hungry but gulping for air because my discus wouldnt even come to eat. Luckily I have 2 spare pump and quickly put it in the tank. They did fine right away after I put the pump in. I was wondering what is wrong with my water? The temperature is ok its at 81 degrees, and the fish were all swimming fine when I left. When I just got home I barely turn on the CO2 for not even a minute and they all went to the surface. I just did a water change yesterday also. Should I lower the temperature down since its summer time and 81 might just be to hot for them.

 

[tazcrash69]

Warmer water will hold less Oxygen than cooler water.
Cool it down a bit if you can, or if you can't try increase the surface agitation.
Also, my tap water generally comes out with quite a bit of dissolved CO2.

 

[Glouglou]

Not enough oxygen

What’s happening in your tank is name:Eutrophication

http://en.wikipedia.org/wiki/Eutrophication

Immediatly an aerator will bring oxygen to your water but will not by itself improve the overall quality of your water. You can see in the link all the causes and effects there.

What I will do:

1: Keep CO2, you need your plants to capture nutrient in the water and release oxygen. The CO2 do not deprive or reduce oxygen level (in some extent)

2: change half or more of your water with well balance water

3: add some powerfull pump to circulate your water but not to much the surface or lost of CO2

4: be sure to have proper lighting, and nutrient in the water

5: add some plant mass

6: change enough water every week

You should enjoy (and your fish to) a better quality of water soon...

 

[sherry]

just to add, I'm having good luck with a steady ripple in the water from a power head below the surface... got the idea from those that came before me