I use
this light from Marine Depot for my 2.5 gallon tank and it works really well plus with LEDs there is no heat and it should last 5 to 7 years before it need to be replaced. Mine is a low tech tank but I grow Crypts, Fissidens, Subwassertang, Rotala, and flame moss, in AquaSoil so it's enough light to grow most anything.

I realized the first photo didn't show the light fixture