Re: shrimp deaths

[Roger Miller <rgrmill at rt66_com>]

On Monday 08 July 2002 01:48, Wayne Wah wrote:

> Firstly, thanks John Wheeler and Alex R for their help about my shrimp
> death. It seems like chloride is the culprit. Before I get the
> dechlorinator, I would like to know if it ONLY precipitates chloride ions
> and not other nutrients useful to plants.

First, the idea that chloride has anything to do with your shrimp deaths is 
very unlikely.  Chloride is one of the 7 most common electrolytes found in 
water.  It is ubiquitous, we all have it in our water and it is nothing to 
worry about.    For all intents and purposes chloride is biologically inert 
at concentrations found in fresh water.

Second, chlorine is a chemically different beast.  Don't get the two 
confused.  When dechlorinators "deactivate" chlorine they ultimately turn it 
into chloride.  Chloride does not get turned into chlorine by any common 
natural process, biological or otherwise.

There is little you can do that removes chloride from water except anion 
exchange, RO and distillation.  It doesn't form precipitates with anything 
until concentrations become very high, as when sea water is evaporated to 
precipitate salt.  Table salt is 60% chloride.

I've been keeping C. japonica for a couple years now and I dose my tanks with 
potassium chloride.  And potassium iodide, for that matter, though I don't 
find the iodid as useful for the C.japonica as it is for ghost shrimp.

I've read that C. japonica inhabits fairly brackish waters in it's native 
habitat.  If so, then a lack of sufficient chloride is a more likely cause of 
problems then is it's presence; brackish waters commonly contain into the 
thousands of mg/l of chloride.

Other possibilities might be; your supplier is selling you stressed animals, 
your tank carries a pathogen that kills the shrimp, your water contains 
lethal levels of a metal (copper for instance) that the shrimp are sensitive 
to, or that some other additive that you are using in the tank is toxic to 
the shrimp.  

Roger Miller