For the most part this is accurate. Stainless steel is an alloy of
iron, nickel, chromium, plus other metals in minor percentages.
Freshly worked stainless steel will rust readily. It is usually
passivated by dipping in a solution of potassium dichromate and dilute
nitric acid. This replaces the surface iron atoms with chromium, and
results in a rustproof surface.

PlainBill

On Sun, 15 Jan 2006 14:48:38 GMT, (Roy) wrote:

There is just as many different alloys of stainless steel as there is
types of wood........and for the most part most of them are fine to
use in fresh water, and lots of them in sal****er environments. The
ph range you use attain to keep fresh water fish or marine fish is
usually fine for these materials........and contrary to belief so is
copper and brass safe for the most part. It will not leach unless PH
is too low..........and for it to leach and have ph too low, odds are
the fish are toast anyhow at that point.....

You may find rust on some stainless steel but odds are its not the
actual stainless that is rusting, its the fact it was not passivated
and cleaned after it was made and the rust you see is from tooling
used to roll the sheet stock or form it or machine and cut it....Just
drilling a hole in stainless steel with a high speed steel drill bit
will transfer some regular steel to that SS surface and make it rust,
same as if you wire brush it with a carbon steel wire brush, it leaves
a film of transfered material on the stainless which is prone to
rusting.......


On Sat, 14 Jan 2006 16:50:04 -0800, "Daniel Morrow"
wrote:
Bottom posted.
Kevin wrote:
Hi group,
I am in the process of designing a formal pond for my Townhouse. In
the interest of making my life easier in the future, for maintenance
purposes, I am thinking of using stainless steel to create some of the
filter components.
Is anyone aware of any kind of detrimental effects that stainless
steel may have on the water chemistry which may affect the fish?
Is there a preference as to the type of stainless steel? I have
found good sources for type 304 and type 316 mesh in various mesh
counts. The main difference between the two from what I've read, is
that type 316 has molybdenom added to the alloy. This makes it far
more resistant to oxidation, much stronger and resistent to thermal
dispertion. I like the idea of oxidation prevention, as well as the
added strenth, but the thermal factor doesn't even come into play for
my purposes. That is unless my pressure washer finds a way of
producing temperatures approaching 1400 degrees.
My main goals are for use as hardware (that will be exposed to the
water), removable baskets to hold filter media, and screening for
filter openings etc.. I may even consider machining or buying some
fountain nozzles or spray nozzles for distribution of water over
filter media.
Any input would be of help.

Thanks
Respectfully
Kevin

I've heard that stainless steel is supposed to be totally safe with fish and
invertebrates (i.e. snails and plants as well I think). Sorry but that's all
I know. Good luck and later!