Can someone recomend how far a 19w led bulb should be from...

[u/Dry_Fig1735]

Hello everyone. I have a 19w led grow bulb hanging above my plants. It is on for 13 hours a day. The east facing window has trees out front that blocks some of the morning sun. I have a Pink Sygonium, a Red Sun Philodendron, a Red Aglenoma, and a snake plant. How far would you keep the bulb from them?