Should I worry?

First off, hello everyone! I'm glad I found a new message board to frequent.

Okay, I have a 10g, heated (at 76 deg)and filtered tank that I have a male betta in, who seems to be doing fine. I'm sure he appreciates it much more than the small cup I rescued him from! I did try some water strip tests that show nitrite and chlorine are good, though I need to lower the pH down from 8.0

After doing some reading here, I chose three corys yesterday as tankmates with my betta. However, after adding the corys, they all seem to just sit in the bottom. I've seen two of them swim around for short periods, but for the most part they sit at the bottom apart from each other. I dropped in two sinking shrimp pellets but found them today all cloudy and untouched.

I know this is only the second day, but since they aren't eating or being very active, should I worry?

:help: <---Thank you all!

Thanks for the reponses!

I do have some "pH Down" but it advises me to not drop the pH drastically so I've been doing the recommended dosage every other day.

I do have a "cave" and a nice shaped piece of driftwood that they can hide under, though I haven't seen them utilize either.

Thanks again, I'll just have to keep an eye on them.

Well I woke up this morning to find one of the corys dead.

I did notice right from the start that one never swam around and just sat at the bottom, swaying with the filter current. The other two at least swam a bit when with the light off ( as someone mentioned).

So, I'll be off to get a replacement and maybe an extra cory. Hopefully they'll start eating.