Re:Copper Sulfate in fish food

[Moontanman at aol_com]

In a message dated 4/8/03 8:41:57 AM Eastern Daylight Time, 
Aquatic-Plants-Owner at actwin_com writes:

> The ingredient lists Copper Sulfate as a main ingredient. Copper is 
>  poisonous to invertebrates such as algae eating shrimp. There is always 
>  left over food that the shrimp eat. The shrimp seem to be disappearing. 
>  Is this a reasonable conclusion?
>  
I checked my OSI fish food and found that indeed copper sulfate is listed as 
an ingredient. I'm not sure I would call it a main ingredient since it is 
almost last on the list of ingredients. In a list of ingredients the 
ingredient listed first is the main ingredient as you go down the list you 
get to things that are really just traces. since copper sulfate is poisonous 
to both fish and inverts in anything less than trace quantities it seems 
unlikely fish food would contain anything but trace amounts of Copper 
sulfate. I breed crayfish and shrimp and have never had any problems with 
copper build up in my breeding vats even though I seldom do any water 
changes. I would bet that copper from plumbing would be a greater threat than 
copper from food.

Moon