Redtail Shark

Question

Yestderday I bought a redtail shark and a bottom feeder to go with my lone peppered cory. I noticed the tank was very cold today (as it doesn't have any kind of heater) so I put a heat lamp on it. All day the shark was huddled at the bottom with the bottom feeders. Soon after putting the heat lamp on, both the bottom feeder and the shark started swimming with their mouths to the surface. Upon returning home today, I noticed they are still doing this and the shark has lost almost all of its black colour and its fins are also dull. The bottom feeder also appears to be getting dull too.

The cory is looking almost HEALTHIER then before, while the two new ones don't appear to be doing so good. Also, I believe the cory may be bullyin

Answer
Hi Ruth, I'm not sure if you knew this but corys like their water kind cold around 70 degrees or even around 68. The shark and bottom feeder can adapt to really any temperature and I think the heat lamp may have disrupted them a little. I've never used a heat lamp. If you want to keep the temperature consistent I would purchase a heater I love mine and it is worth the buy.