Re: shrimp deaths

[Roger Miller <rgrmill at rt66_com>]

On Tuesday 09 July 2002 01:48, John Wheeler wrote:

> I just started using Amquel. I'm interested to see if
> it leads to more shrimp deaths based on this new info
> to me.

The amount of chloride you generate by using a dechlorinator is 
insignificant.  On the other hand, according to Wright the Amquel itself 
might be lethal to your shrimp.


> Wayne (I think), nor Roger, mentioned how much KCL
> they were using.

I does 1/2 tsp / 35 gallons.  That's about enough to add 12 mg/l of K+ and 11 
mg/l of Cl-.  That's on top of 22 mg/l in my tap water, for a total of 33 
mg/l.  The actual chloride concentration in my tanks would be higher than 
that because of evaporation and other chloride sources.

The drinking water standard in the US is 250 mg/l chloride. Other countries 
probably have similar standards.  As a result, some of us could be keeping 
their shimp in tap water with quite a bit more chloride than I have in my 
water.

> If they do live in brackish water then Chloride
> without the Sodium would be a problem, right?

I have no reason to believe so.  There is no unique association between 
sodium and chloride while they're in solution.

> from Aqualog Special "Shrimps, Crayfish, and Crabs in
> the Freshwater Aquarium", Uwe Werner, author:

[snip]

The page at 

http://suiso.com/ebi.htm

describes their natural habitat as marsh- including brackish marsh - and 
provides some guidance on care.  By and large any brackish or fresh water 
animal can withstand large variations (1000s of mg/l) in salinity and 
chloride content.

> Very possible, however; no deaths since I stopped
> adding KCL, 1 year ago, and no newly bought shrimp in
> one of my tanks. Some are over 3 years old. When using
> KCL, I would lose a shrimp once a month, per tank, in
> a stock of about 50 (shrimp) all together.
>
> I know this is anecdotal. YMMV, Blah, blah blah.

Anectdotal is usually OK if you can come up with some backup for your 
conclusions.  It's going to be hard to show that either potassium or chloride 
at "fresh water" concentrations is toxic to anything at all.

Roger Miller