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Using hypochlorite to clear murky water

I am an art student and getting my degree show together at the moment. I am using large glass tanks of water with parts of trees submerged in them. The water has become very murky and I was wondering if chlorine would clear some of this. I am a bit worried about trying this as the glass tank is held together with silicone and I am afraid the chlorine will dissolve the silicone. Any suggestions?

pam corrie
art student - swords, dublin, ireland
2003

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I've never tried to clear murky water like this, so I'm totally guessing. But, while I doubt that the bleach will attack the silicone, I do not doubt that it will attack the parts of trees because of its high caustic content. Water treatment plants would use alum (aluminum sulphate) or ferric chloride ⇦this on eBay or Amazon [affil links] (in very low concentration) to remove turbidity; as a guess I think that is what you should use too.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
June 2,2003

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Chlorine will not attack silicone, so it would be safe to do what you want, but you may be better off doing something less extreme. The chlorine and the high pH of hypochlorite may well attack the wood and make it fall apart. Do you know what has caused the murkiness? Is it the wood giving off a colouration, or is it bacterial of fungal? Try passing the water through an external pump with a good filter. You can also pass it through an activated carbon filter to remove any colouration. Furthermore, depending on what caused the discolouration, it may be advisable to pass the water through a UV light cleaning unit. All of these things can be obtained from any good water garden or aquarium centre. You may also want to try using Kieselguhr, a resinous substance used in brewing to clarify the beer. The water industry has used alum (aluminium sulphate) to do the same sort of job, so that may help you too.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2003