Re: Aquatic Plants Digest V1 #239

>From: huntley at ix_netcom.com (WRIGHT HUNTLEY )
>Date: Fri, 11 Aug 1995 13:38:00 -0700
>Subject: Re: Death In a New Plant Tank

>The solution is to have a serious conversation with your water dept. 
>engineers, and find out what you are dealing with locally.

Most local water authorities will provide a copy of the water
analysis that their labs carry out during the year of both the
raw water and the treated effluent that arrives through your tap.

>How much sodium thiosulphate is an appropriate amount to use, and what does it 
>do with chloramines? I have photographic sodium thiosulphate on hand, but 
>wouldn't know how to use it if we did have that hypothetical emergency. Is 
>trial and error, with a chlorine test, the best way?

Sodium thiosulfate is not toxic to fish in the amounts of which we
are discussing. 7.4 units of sodium thiosulfate are needed to neutralize
one unit of chlorine at pH 11.0. At neutral pH, twice as much is needed.
Unfortunately, my understanding is that many manufacturers base the
dosages advocated on the bottle on those required at pH 11.0. This
means that one really should be doubling the dosage. If you have the
pure stuff, it should be relatively easy to figure out what you
require in your area. I stole this from a good article on chlorine
treatment posted in the fish area on Compuserve two years ago. I believe
the dosage refers to chlorine, not chloramine. For chloramine
you might want to double again.

>Does anyone know if sodium thiosulphate precipitates Fe, Mg, Cu or other
>trace plant nutrients?

No idea, but I really wouldn't expect so.

>From: Stephen.Pushak at hcsd_hac.com
>Date: Fri, 11 Aug 95 17:09:31 PDT
>Subject: Milfoil (Myriophyllum aquaticum) grown emersed?
>The Myriophyllum aquaticum is doing quite exceptional under the 250w MH
>and has reached a length of about 3 feet. I had already chopped the tops off
>this and replanted them. I notice the leaves do not resemble the original
>shape in either of my tanks. When I first put it in the 49 gal. the leaves
>were highly divided and fairly short (somewhat like feathers?). Now the
>leaves are branched nearly so much and are many times longer. I'll try
>to diagram a leaf below. Is it possible that these plants were grown emersed
>at the plant farm? What might account for the difference in leaf shapes?
>The original leaves turned reddish brown and look dead. The new leaves are
>greenish to golden-green in bright light. Quite attractive :-) (bragging

The leaves of some myriophyllum species (M. alterniflorum) differ
greatly in appearance depending upon the substrate in which they
are grown. The leaves of the above species were much longer in
loam and peat than in sand. (from Aquatic Botany 10: 383-388)

There apparently are quite a few species of myriophyllum in North
America, often difficult to identify and distinguish.