I thought iodine is not a good thing in fish tanks..

"The poison is in the dose," as Paracelsus said. Iodine is a necessary
nutrient. It can also be poisonous if you use too much. I wouldn't dump the
iodine directly on the shrimp, but used as recommended, it's safe.

. or is iodine in
"iodized salt" and "iodine" in kent marine iodine different?

No, iodine is iodine.

I thought one
doesn't want to use iodized salt because of iodine in the salt, but is there
something else?

You can use iodized salt in a fishtank. A lot of people do.

The old books that tell you to only use kosher salt or aquarium salt date from
the days when arsenic was used to keep table salt free-flowing. They don't put
arsenic in table salt any more, so it's safe to use in fishtanks.



Leigh

http://www.fortunecity.com/lavender/halloween/881/