Please help ID this cactus

I am trying to post a picture of a cactus I've been trying to identify for years and years. Now I'm not sure how to post pictures but if you can view this can you help ID this cactus? I saw the one it came from five or six years ago and watched it bloom with 6" flowers that only lasted a day or two. It was only the size of a quarter when I got it. I've been trying to get it to grow so I can see those flowers again but I'm not sure what it is and I wanted to look up how to take care of it best. I'm great with flowers and vegetables but this is the only cactus I have. Suggestions?? I was thinking I should transplant it. It is in a pot with potting soil and some large rocks in the bottom for drainage. What should I use instead?

Thank you
Aaron

 

The sidebar has a link on how to attach images....

 

Thanks. here are the pictures of the cactus I am trying to identify.

 

not sure of the species but get it to the light! That skinny growth isn't right, it's reaching for light. Indoors needs a bright window at least if it's not dormant in the winter.

 

And when you re-pot, try to get Cactus Mix (available at most garden centers) instead of potting soil.

 

Thanks I'll do that. As for light, I have it in the window that gets the most sunlight, I don't know if I'm in the best part of the world though for growing cactus. Maybe if I add a full spectrum bulb in my living room to add to the limited sunlight it gets just because the climate sucks up here.

 

echinopsis of some sort, heres mine a few years ago.

 

i think it also might be one of these, or even a hybryd, heres a pic of mine from a few years ago, and a year before that when i picked it up at a yard sale (highly etoliated)