Hi. I have 5" Santos Mahogany floors in my house that were site stained. There are many places (at least 7) where 2 US quarters fit in the gaps and where I also can see the tongue and groove. The gaps are very obvious and look ugly. How can I tell if there was a problem with the install? We have humidifiers at 35% throughout the house, but the winter made the gaps worse. Any advice would be appreciated! Thanks.

Those are pretty wide gaps. How many rooms and when was your floor installed?
Was the flooring tight when it was installed? Heating season will cause some gapping. Your location?