Just add 1/2 volume of your starter as boiled/ cooled water. Mix and you should be about 1.040.
Don't Bogart that starter!
Any gravity over 1.040 makes alcohol, some new yeast. Dropping it will increase yeast production.
Stirring and oxygenating it will increase your rate.
Variac runs aquarium pump through HEPA filter and down pipe right into center of vortex.
Wort is 1.040 OG with 5 drops of foam control. ( 15 oz DME to 1 gal water in a 5l Erlenmeyer )
I since dumped the Variac and went to a blowoff jar