[seemfrog]

Hi all,

Hopefully this is an OK forum to post this question, and hopefully someone has some ideas!

Background: I am a fish biologist and we recently put a pool chlorine tablet into a Plexiglas box to obtain a clear box to house a video camera for fish monitoring.  We finished this monitoring and since we couldn't pour this water into the creek, we used a sump pump to pump out the chlorinated water (which smelled very strong) into a metal horse trough (to hold until we figure out what to do with it).

Plan: our thinking was by leaving this water out in the open the Chlorine would dissipate (wording?) and the water would evenutally be OK to dump onto the ground.

Concerns:
1) Will this really happen?
2) Will the metal horse trough be OK to safely hold live fish in several months?
3) Once the Chlorine is gone will there be residual solids?
4) Is there a good method of cleaning out the materials (sump pump, hose, horse trough, "clear box")

My thoughts: my mom always told me that Vinegar neutralizes bleach (doing laundry), so is this the same situation?  Could we do a half and half V/Water rinse?  Would any dangerous reactions occur (gases)?

Thanks so much for any thoughts or ideas!

[pantone159]

My thoughts: my mom always told me that Vinegar neutralizes bleach (doing laundry), so is this the same situation? 
Would any dangerous reactions occur (gases)?

Yes, dangerous reactions occur when mixing bleach and acids (e.g. vinegar), namely producing toxic chlorine gas.
You might try vitamin C, which should reduce chlorine to non-toxic chloride ion.

[Borek]

How much water? How much chlorine tablets?

No idea about their exact composition, but it is probably some sort of mixture containing soidum hypochloride. If so, vinegar will definitely help to decompose it.

[seemfrog]

uh oh, I have two oposite opinions... looks like I'll need a third to break the tie!

So the water with one pool chorine tablet is in a metal horse trough - about 50 gallons of water.

It is outside on the back of a truck right now, we are hoping the chlorine will dissipate out of the water making the water safe enough to pour out on the ground (we are at a hatchery and there are concerns about harmful substances to fish).

So, one questions is will this happen eventually, if not, what can we do.  One person mentioned Vitamin C, which I've never heard of doing, is this using a powder form?  Will it then be safe to pour out?

and the other is after we dump the water, how do we clean the gear for safe use with live fish later.  The other person thought a vinegar rinse should do the trick, the first thought it would turn to toxic gas.  Even if it turns to gas, if done outdoors, can this be done safely???

thanks again!

[Borek]

Vinegar will acidify the solution, forcing hypochlorite to decompose. Vitamin C will not only acidify the solution, but will also react with evolving chlroine, reducing it simple chlorides.

How large was this pool chlorine table? It is not very unlikely that while the smell seems to be strong, solution is already relatively safe. If acidified with vinegar and left for several days it will probably get completely safe. You may also think about adding sodium sulfite (Na₂SO₃) which is probably the safest way of dealing with chlorine.

[seemfrog]

Thanks for your replies,
it has been sitting for 2 weeks now, and I haven't smelled it since, so it may be safe already as you said.  One of our employees was going to bring in a pool kit to check the chlorien level.

Any idea how much Vinegar should be poured in if we go that route?  Should the person be careful not to inhale while standing over the solution?

Where might I get the recommended: sodium sulfite (Na2SO3)?

thanks again