The volume of water allowed to flush toilets has steadily decreased. Problems related to flushed materials have increased. See a pattern here?
unless it’s new construction with a properly sized main line, you can have problems putting low-flos in older housing. they may flush fine, but may not have enough water to get everything through the main ‘line into the city sewer.
good tricks for folks to consider is after a dump, to then take your shower in the same bathroom. or do some wash. or if you had cleaned a sinkfull’of dishes, let’the sink water down the drain. this way you’re using wastewater you’d be getting rid of anyway to help out. of’course you could always flush twice but may defeat the purposeof the low-flo.