Right and wrong. Biobor Kills algae,(hormoconis resinae) but micro organisms grow in the water in the fuel. If you fuel contains no dissolved water then the algae has nothing on which to grow, If you completely drain your tanks, no fuel = no water= no algae !
The elimination of water goes a LONG way to eliminating algae growth, Mr Funnel does a very good job here.

I’ll add another point here. here. HR can cause corrosion of metal in contact with it as some fullsize manufacturers and operators have found to their cost. Gaspar recently sent to my group his video of machining of his pumps for the new 90 and 120 engines.They are machined on his Datron cnc machine to a tolerance of .01mm for max efficiency. .HR corrosion, and dirt could easily destroy this tolerance so:
Do everything possible to eliminate water from your fuel.
If you still have water problems use Biobor.
Filter, filter and filter again, your fuel so that jt is perfectly clean before it gets to the pump.
Seal off your tanks to stop air getting in/out with temperature changes which can induce moisture which is then absorbed by the fuel. ( Kerosene is quite hygroscopic)

Coffee finished, Ill leave it there !