MYSTERIOUS WATER PROBLEM

[Ward]

My new 180-gallon tank water measured 0 PPM for Cl, NH3, NO2, and alkalinity. Temperature was 83degF, pH 7.4 su, and NO3 was 12 PPM (presumed biological cycling was complete.)

Added clown loaches and red-tailed sharks.

The loaches died overnight; the sharks are fine. Vaguely recollect that if alkalinity is low enough, pH cannot be acurately measured. What else could have killed the loaches?

 

[Toirtis]

Well, to start with, that water temp is a bit high (by about 4ºF-5ºF)....a lack of dissolved oxygen in the water, combined with the stress of being moved into a new tank, may well have killed the loaches.

 

[Fishyfanatic]

Do you have any salt in the tank?

How did you cycle the tank?

 

[Ward]

Water temperature would be even higher if not for 20 gallons per minute recirculation across the top of the tank. This should provide enough dissolved oxygen. No lid, no lights.

No salt.

Relocated an Eheim 2229 from another system. Tested with a shot of NH3.

 

[Toirtis]

And how was the tank cycled?

 

[afishoutofh2o]

Here is an excellent resource on Clown Loaches (Botia macracanthus). Since clown loaches are scaleless they are very sensitive to water quality issues.

The Loaches.com website is a very interesting read!

 

[malkore]

How was the tank cycled, and what is your water source?
Low alkalinity means you have little buffering ability to prevent pH swings. pH should still test properly, but is far from stable.