Amonia in commercial green algae food?

[goog]

Interesting....on the last day of 6 week quarantine cycle my large yellow Tang started to to breath fast and flash. No other abnormal physical signs. Given that the previous six weeks was absolutely perfect and my QT was very well established, water quality was near always near pefect. I was somewhat perplexed. A quick water test revealed a trace of amonia. I brought my emergency water supply up to temp, fine tuned Ph and salinity and acommplished a large enough water change to bring the amonia back to undetectable. Within a few hours the Tang was 100% back to normal. My next question was what caused the amonia spike? When I went to my LFS they were out of my normal brand of green macro algae so I purchased another brand. The introduction of the new macro algae corresponded with the spike in amonia. I took a small piece of the new algae soaked it in a dish of of tank water for a few minutes and tested for amonia. Sure enough it read about 2ppm. A friend of mine in the industry told some manufacturers sometime use amonia in the drying process although this brand claims to be sundried. Has anybody seen this before? He also recomended using raw unprocessed algaes like gracilaria (as sugested by lee).

[leebca]

That would be a new one on me. I never heard of ammonia being used in the dehydrating process. I wonder if it wouldn't damage or destroy some of the algae. I mean, it just doesn't seem logical. If you can find a manufacturer that does use ammonia, I'd like to know how they use it for this product.

I would also test some of your 'normal' brand of algae. I would suspect that bacteria would be at work trying to 'eat'/decompose the algae as it was drying, so I wouldn't be too surprised to find a trace of ammonia in the experiment you performed. Since, in a display system, with an active biological filter, there should be no signs of any ammonia. I mean, your fish will produce a 'shot of ammonia' when it defecates and you shouldn't find any ammonia spike at that moment.

The large water change was the right thing to do, however!