Lisa,

I had the same thing going on recently with my 180L tank(thought I had
an extrememly planted aquarium), I actually used a product called
"cycle" that contains dormant beneficial bacteria which is probably
simlar to the product you used. It took about a month to get some
readings, it sounds like your gourami's are happy if they are producing
bubble nest's. I wouldn't worry about not having any ammonia,nitrites,
nitrates ect. It is actually a good thing as u probably know.
Happy Fishkeeping

--Wez