Dead Betta - Advice so it doesn't happen again?

[peridotclover]

I know this doesnt count as a disease or emergency, but I wasn't sure where else to post this. I woke up to find my little girl dead this morning, and I have no idea what happened! I was hoping someone might be able to offer advice as to possible causes, so that I NEVER let this happen again!

She was in a 1 gal, heated, unfiltered, with 90% changes every other day. Fed pellets / bloodworms twice every day. The only thing that I can think of was that I had noticed her poop was whitish and kinda stringy. Could it have been internal parasites? (I did get her from Walmart... about 2 months ago.) And whats with the weird discoloration on her body - is that normal for dead bettas? (This is my first )

Here are alive / dead pictures.

[LebronTheBetta]

Yes, she could have died because of that. And she's pale because she died. And if you want another future Betta in a Gallon, you could change the water's amount. I say 1 50% and 1 100% per week. I'm so sorry she died. She was beautiful, though!

[tanseattle]

I am sorry. It is always sad to let pet go..