Can a Java Fern or Jasper Rock be killing my fish?

Well my Red Fish died after a year with me... After the funeral I got
a new betta, this one is blue and named Jaws. Jaws was fine the first
day, but this has quickly changed. Second day he ate, but hung out at
the bottom. Today was worse: he wouldn't eat, and was laying
dead-like on rocks at the bottom. The water is fine, he's in a 6L /
1.6 gallon container. I had a java fern and a piece of Jasper Rock in
there along with some stones. I know the stones are all right, cause
they were with my other fish for a year with no problems. Question,
the Japser Rock - anyway it could be harming the little guy? Or
perhaps the Java Fern? The fern is potted in this plastic container
with a cottony like thing around the roots.

Please help, don't want to lose two fish in one week. I changed his
water again, taking out the fern and Jasper to see if that helps.

J

From your last post, you don't test the tank water for ammonia, nitrites,
nitrates or pH. The tank also doesn't have a heater or a filter. If the water
is "fine" ammonia and nitrites would be zero, nitrates would be under 20ppm, the
pH would be close to 7 with little variation , and the temp would be a very
steady 80 degrees. Its probably neither the java fern or the rock that's
killing your fish, its poor water quality from an uncycled tank.

You may want to read up on tank ca
http://faq.thekrib.com/
"cycling" a tank
http://faq.thekrib.com/begin-cycling.html