From: laurence@cco.caltech.edu (Dustin Lee Laurence)
Newsgroups: rec.aquaria
Subject: Re: [M] Need suggestions on cowfish, rock anemonies, etc.
Date: 21 Jan 1993 20:52:11 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: sandman.caltech.edu

glee@athena.mit.edu (Gilbert Huppert) takes exception:

[I mention using NaOH to kill Aptasia polyps]

[ hopefully clear warning deleted]

>I personally think that this is very dangerous, especially for someone not
>trained in dealing with chemicals.

I partly disagree.  I don't think that just anyone should try this trick,
and I thought I made that clear.  However, the word _very_ is perhaps
too strong.  Any organic laboratory uses the stuff in great quantities.
With _proper precautions_, NaOH is not a great deal more hazardous than
the nastier household chemicals, and quite possibly less so than doing
your own brake service or wiring the hood of a saltwater tank (both of
which I have done, though I won't do the brake service unless I have
more competent supervision).  (Do they still sell the drain cleaner that
was nothing less than a sulfuric acid solution?  Probably not.)

I said that if you don't have any idea what the precautions are, I didn't
recommend that you attempt this, but if someone is determined I'd rather
they get some help from me than try it with no help at all.  However,
there are clearly a number of rec.aquaria readers who have the knowledge
and safety equipment, and there is no reason that I see to reduce my
posts here to the lowest common denominator that we see other places.
I would imagine that a post about wiring a light hood and stand for a
marine aquarium would be of interest to those readers who have the
appropriate skills, and I would argue that here the danger if a mistake
is made are probably greater than making sodium hydroxide.  It may be
easier to ruin your eyes with NaOH, but it's easier to die from current
flowing from your arm past your heart to a wet floor.  (Not to say that
you couldn't kill yourself with NaOH if you tried hard enough...)

Side note: as education is why most of us read *.aquaria, I suggest that
it would be a fine idea to put a few paragraphs of chemical safety and
handling info in the FAQ (no, I don't consider myself competent to write
it).

[more hazards of NaOH deleted]

Since you can't have missed my warning, I presume that you consider it
to be insufficient.  Thank you for adding more details.

>My opinion is that you might as well use hydrochloric,
>or any other strong acid, just as easily, and with the same dangers.

Again, I partly agree with you.  As far as the dangers go, HCl is
perhaps of comparable risk, but I'd far rather mess with NaOH than
sulfuric acid (which, unless memory decieves me, has fumes far more
dangerous than either of the other two).  I don't consider HCl to be to
dangerous to handle, but I also have access to glassware, gloves,
goggles, an apron, a working hood, and the advice of more knowledgeable
people.  Each reader must assess his or her own abilities and equipment,
as they are in a far better position to do this than I.

As for usefulness in controlling Aptasia, I disagree.  I believe that
NaOH is far better than any acid, though I'd be interested in hearing
arguments to the contrary.

>If you inject the solution directly into the tank, you are risking serious
>pH problems.

True, if you are foolish enough to inject too much.  I have never used
more than a half a cc, and probably quite a bit less.  My solution is
quite strong (rather stronger than optimal, I would say), and it takes
very little.  Again, I don't recommend this technique to those who
are not ready to give it a bit of thought first.

>On the other hand,
>Ca(OH)2 is nowhere near as dangerous, and you should be able to make a 
>suspension fairly easily, and inject this into your target inside the 
>tank.  

Read the post.  Calcium hydroxide has not worked well for anyone I
know of.  (Though perhaps someone on the net has a different story?)
A technique that does not work is not an improvement.

>Please think very carefully before adding any chemicals to your reef.

This should go without saying, and I heartily second it.

-- 
Dustin Laurence       "As sensitive and broad-minded humans, we must never
                       allow ourselves to be in any way judgmental of the
laurence@alice         religious practices of other people, even when these
caltech.edu           people clearly are raving space loons." -- Dave Barry
Newsgroups: rec.aquaria