OK dude seriously, I know, I have done the research, IF you read the whole thread you would have seen it was NOT me who decided to fill MY tank, it was MY SPOUSE trying to be helpful and perform a RANDOM ACT OF KINDNESS. I also understood that tap water would lead a whole bunch of algae problems BEFORE I put up this thread. I was trying to make sure that's all I would have to worry about or if there were other issues that I was not aware of. BUT that's ok cause I drained the tank and the responsible party has now been educated as to why we use RO/DI instead of just tap water.