Black tetras acting funny

[BrutusPleco]

I did a 25% water change as usual in my 30 gal. tank. My 4 black tetras are up close to the top of the water not doing anything except looking STRESSED. All other fish are doing great:

1 - 3 inch silver dollar
6 neon tetras
2 plecos
2 Julii Corys they are so cute!!
1 small dark-orange goldfish
1 ghost shrimp

What could be wrong? They have always been very active!

 

[vega]

Do another round of water change will definately help.

 

[lmw80]

Welcome to Aquarium Advice!!

What are your water parameters? Tetras tend to be sensitive so if anything, they would feel the effect first. Are the neons showing any signs?

 

[BrutusPleco]

My neons are fine! This morning the black tetras seem to be "more" normal. At least they are swimming aronud now instead of hovering on the top! I've had them for about 6 months now and they have never acted like that, so I was somewhat alarmed.

I use those dip sticks to test the water. But also have the more advanced ph, nitrate tests, with liquid drops, etc.
I try to make water change temps at 78* . My nitrate has never been below 30. After testing tap water at that degree, it is 30. So I am assuming :? that my tap water has high nitrates. I also have live plants which seem to be not fairing well so am looking at getting a different bulb. The water has gone from hard to soft since adding the plants.

Nitrate 30
Nitrite 0
Hardness soft
Alkalinity betwwen 80 and 120
Ph goes between 7.2 and 7.8
Sorry this is so long. Appreciate your help tremendously. My lps seems to have the ho-hum attitude. Thanks again!!!!

 

[tsaraber]

A drop in PH might cause this, as well as a too high temperature.

I woke up one morning and ALL of our fish were hovering at the top of the tank. The PH had dropped to 6.8 (from 7) and the temperature was around 86 degrees. They really perked up after I got those two things fixed.

 

[BrutusPleco]

I'm also wondering if adding a large silverdollar that came with a used aquarium that I'm doing a fishless cycle might have upset them. Seems it happened the same day. the siverdollar is very mellow but very large. Will be putting it back in the 35 g. when it's done cycling. Plus adding a couple more silverdollars. Then when fall is here will be adding 2 plecos that are in a pond to clean the algae. As I don't think plecos winter well in cold weather! or cold water!!