pH too low for tetra?

[Submo]

Hi,

I've added 3 lemon tetras and 3 black neon to my 4 years old tank a week ago. The past few days i notice the lemons were bumping up and down against the glass with their noses. Are they sick? This morning i noticed one of them have white bits on its mouth. The test for the water is 0 for ammonia and nitrate, ph 6.2 ... is it too low for lemon tetra? I also have 4 glowlight and 1 x-ray tetra in the tank (10G), neither those nor the neons were exhibiting those behaviours.

What's wrong with my lemons? Any suggestion?

 

[victimizati0n]

what is the temp? what are the nitrates?

 

[happychem]

What's your KH?! That's a really low pH and if KH is low as well, you should be worried about a crash. It's not too low per se, just symptomatic of a potentially bigger problem. Are you injecting CO2?

 

[aquariumfishguy]

6.2 is not too low for these fish, but you cannot have zero nitrates and zero ammonia or nitrites. You have to have some reading.

 

[RustyRay]

Ammonia exists as the ammonium ion (NH4) at an acid pH. And the ion is harmless. So, in acidic water, ammonia is not a concern. Nitrite is a major concern and so are bacteria.

A pH of 6.2 is not low at at all for Tetras. I've read of an experiments in which the pH for tetras was dropped to about 4 with no harmful effects on the fish. Of course, bacteria die off at this level which is bad for aquariums.

At a lower pH the water parameters are less stable and swings in chemistry can occur which will stress fish. I would perform several small water changes until things are more stable.