This is why Bill said on an annual basis it will flush out to be close to the same but along the way they will vary.

(For instance, flush the current pipes to clear out any partial blockages)What options are worth looking into for a separate system?

Flush, bleach, swish, flush again...done.I have saved about 1000 hours of my life and countless miles & gasoline & vacant units because I can't show when the tenants are available. 

People who pay market rents make way more than the median. as for Sacramento, prop 21 (oppressive statewide rent control, sponsored by a nut) just got flushed down the toilet by CA voters.  

Take the drain plug out run the brush up and down for 30 seconds flush with soapy water problem most likely solved.2) As for the bathroom floor/shower problem. 

The next day my tenant comes home and his toilet is not flushing and is bubbling when the other water runs.

Every flush, load of laundry, shower, dishwasher run all fill the tank. 

I also specify items that can not be flushed and they initial them.

I'm currently flush with work (three projects in hand) so I'll let you know if I find a fourth, which I'll then need to wholesale since I don't want to stretch my crews or my finances too thin. 

I once met a real estate investor who said the trick to successful real estate investing is to keep as little cash in the property as possible; you don't pay a loan off as quickly as you can, rather, you keep it lean so that you are always cash flush and are able to then purchase more properties.