Madagascar Rainbowfish - Bedotia geayi
All rainbows are schooling fish and prefer to have at least 4-5 together to be happy.
Yes rainbows do tear around the tank like crazy fish but if kept in numbers they are more placid.
In regards to stocking, my opinion is the tank is quite heavily stocked.
And your plant have little if any chance of survival with silver dollars in there. They love their salad meals
I agree with LivingArt as to the cause of the deaths, A mini tank cycle, caused by the cleaning.
To explain what has happened... When you have cleaned the tank and filter, you have likley killed off alot of the beneficial bacteria that are required for the Nitrogen Cycle. As the bioload of the tank has remained the same the filter has not been able to process the amonia waste created by the fish as effectivly, therefore poisoning the fish.
Best of luck, I hope all the remaining fish are all ok
Oh, and welcome to one of the forums