I am not sure when it started but it is pretty much thru out the house. When I drain tub water, the drain is real slow, same with any sink, and the most used toilet in the house constantly needs to be plunged. I figured it to be a problem with the main drain lines, but where do I start in resolving, I am pretty handy, and would like to research this before calling a plmber.
In your basement you should have a Cleanout in pipe going up to toilet, get a 1″ ribbon cable and take out Cleanout plug and try to cable it out, if everything is drainning slow then main line is stopped. If you cant get it call a Lic. Plumber.