Is This True?

[Timmy_Bee]

read this online and was wondering if it was true: (the bit about ammonia / ammonium)

Nitrogen Cycle Stages
Stage 1
Ammonia is introduced into the aquarium via tropical fish waste and uneaten food. The tropical fish waste and excess food will break down into either ionized ammonium (NH4) or un-ionized ammonia (NH3). Ammonium is not harmful to tropical fish but ammonia is. Whether the material turns into ammonium or ammonia depends on the ph level of the water. If the ph is under 7, you will have ammonium. If the ph is 7 or higher you will have ammonia.

 

[KittyKat]

Yes, that is kinda true. The only false part is that you always have both, it is just the proportions which vary with pH.

 

[nurglespuss]

And that one can quickly convert to the other if conditions change.

 

[anon02]

Both ammonia and ammonium convert to nitrite which is harmful to fish, so it`s a moot point

 

[Gvilleguy]

Both ammonia and ammonium convert to nitrite which is harmful to fish, so it`s a moot point

It depends on the specific problem you are having in the tank. When my tank has gone through mini-cycles, most often I have a slightly elevated level of ammonia while nitrites stay flat the entire time. So I calculate my levels of un-ionized ammonia to make sure I'm not hitting toxic levels for the fish. I researched this exact issue last week and posted my findings here:

Calculating The Toxicity Of Ammonia In Freshwater

 

[anon02]

I use your conversion chart My point is that evenyually both NH4+ and NH3 convert to nitrite

 

[Gvilleguy]

I use your conversion chart My point is that evenyually both NH4+ and NH3 convert to nitrite

Agreed!

 

[OldMan47]

It is indeed true that low pH situations make the ammonia concentration in water safer than high pH situations. We always tend to use numbers appropriate for high pH situations when giving advice because, as Nurglepuss said, one can quickly be converted to the other. Also, as Anon said, both will convert to nitrites and here is the real rub. When it comes to nitrite toxicity, just the opposite is true. High pH means low nitrite toxicity and low pH means high nitrite toxicity. There is no such thing as a safe condition, based solely on pH for these poisons in your water, so it is always better safe than sorry for me.

 

[waterdrop]

Agree with OM. WD