All my fish are swimming at the top

[Matman1110]

Hello,
I have a 47 gallon tall tank of African cichlids. And most of my fish are swimming at the very top of the tank very close to the surface. They also are staying kind of close together like in a group and not moving that much at the top. I have a yellow fish who normally spends 99% of his day in a cave at the bottom of the tank but now hes at the top so i know theres something wrong. Ive had the tank for a long time, almost 2 years, so i dont think its a cycling issue. When i first saw the fish doing this i noticed the tank was quite dirty and did a 50% water change and cleaned out the filter. That still hasnt helped.

Please let me know what is going on and how i can fix it. Thanks.

 

[fishman3]

hmmm. have you fed them

 

[Matman1110]

yea i fed them last night, but i took a break from feeding them for a day or 2 before that because they started spitting out the food and they didnt seem to want it.

 

[molly100a]

Did you check the water parameters, when mine did that the ph had dropped.

 

[Ziggs180]

A large water change might of changed the PH or the temperature of the tank by enough that it stresses the fish by the sudden change.

 

[Matman1110]

I checked the pH and it seemed to have dropped slightly to about 8.0. Ive added plenty of buffer since then but there hasnt been much change. Temp is at 78 F and ammonia, nitrites & nitrates are unknown.

 

[bruinsbro1997]

My guess is ammonia, nitrites, or nitrates poisoning or some other chemical is involved, or they're not getting enough oxygen.