We are also trying giant duckweed. All are easy to reproduce and deal with during water changes. Temperature of the water ranges from 76-82 degrees fahrenheit. We haven't monitored our pH in over a year, so perhaps we are lucky, the tap is slightly high. We change all of the water in the quart jars once a week.
Fry tanks receive only slight water changes, only to remove build-up on the bottom.
Oh, by the way, we don't use any gravel at all, it makes cleaning tough, and traps some live foods. Aeration is used only in the tanks for the young, not for the adults or fry. Their Breeding Remember, there may be many ways of getting the job done, ours is just one. Most of our males will build nests immediately after water changes. They prefer putting them along a side of the container, or under and around the floating plants.