Airation causes pH change during acclimation

[majolo]

I've read somewhere some warnings not to aerate when acclimating fish after shipping. I think the idea was that the aeration would cause pH to shift, which would lead the ammonia in the water to change to a more toxic form or something... Anyway, this seems like a good thread to ask, does anyone know about this and can you explain it?

 

[rkilling1]

IMO, the idea is sound. Ammonia comes in two forms when talking about fish. NH4, which is less toxic, and NH3 which is very toxic. The higher the pH the more ammonia shifts to the NH3 form.

While a fish is in transit using a non-breather bag, they consume O2 and give off CO2 which in turn lowers the pH via carbonic acid.

So if you were to drive off the CO2 and in turn, increase the pH with a lot of NH4 in the bag, I can see why that could be a problem.

There are some factors that come into play. How much CO2 is in the water, how much NH4, how long the fish is in the bag when acclimating, ect..

I can't say how big of a problem this is or could be. Transit time also plays a big part.