"Our country is being destroyed by incompetent people," said Trump, who devoted large swathes of a jovial speech to poking fun at 81-year-old Biden.
"All presidents should have aptitude tests."
The former President addressed Club 47 fan club members at a convention centre in West Palm Beach, a short drive from his Mar-a-Lago residence.
At a recent rally, Trump ranted about one of his favourite subjects… the weak water flow from water-saving taps.
The President has been fixated on water pressure since at least 2019, bringing it up at various rallies and in speeches.
In February, he told a Town Hall with Fox News’ Laura Ingham that Americans are “not allowed to use water” because of the Democrats.
"They come out with faucets where no water comes out," he said.
"You know, if you go and buy a home. And they know what I mean, the showers. You stand under a shower, and there's no water coming, and you're saying… you end up standing there five times longer."
In August last year, he also complained about how long it takes him to wash his “gorgeous head of hair”.