That Blood Parrot is way to big for that tank dude and soon it will kill everything you have, mixing a agressive fish like that with platies is a no no.
I agree. Your red parrot could grow up to 8 inches which would be way too big for a 30 gallon tank. I was going to turn my 30 gallon into a red parrot tank just because I loved the look on their faces. But I did research and found out that even one red parrot would be unhappy in a small 30 gallon. I suggest you add some more corries and otos. They will be much happier in groups, and they'll probably become more active.