I have a ejector pump system in my basement that is being fed by a toilet and I want to know if it's o.k. to use reglular toilet tissue or other,special paper that will dissolve with water. Do chemicals need to be added to tank?

You can use regular toilet paper.

Just be careful of feminine hygiene products being flushed. Tampons should pose no problem, but nothing heavier.

Nothing else needs to be added to the tank.

This all presumes that you are on city sewer and everything is vented correctly.