75 watt too many?

Philips 75-Watt Agro Plant Light BR30 Flood Light Bulb-415281 - The Home Depot

The bulb you display is an incandescent, not an LED. I think Ray means plain old outdoor LED floodlamps. Forget about the "plant grow" part. That doubles the cost.

---------- Post added at 10:51 AM ---------- Previous post was at 10:04 AM ----------

Lowes has these. I searched on LED Bulbs then refined the search to 100W and 120W equivalent, Flood shape:
https://www.lowes.com/pl/LED-light-b...718,4294564618

Home Depot seems to be drastically reducing what they carry. They show many items as no longer in stock. I searched on LED Lights then Over 90 Watts:
Greater than 90 - LED Bulbs - Light Bulbs - The Home Depot

Actually, I was referring to ordinary outdoor LED floodlights.

While still not perfect, the lumens output is far more important that the watts consumed. That bulb you linked to puts out 700 lumens. THIS Cree lamp puts out 1500 lumens, yet only consumes 23% of the electricity.

Back to your lamp holder, you're going to have a very tough time supplying enough light, no matter what bulb you use, from those distances. You might get away with very low-light plants at the 20" distance, but the current limitation of the fixture will prevent you from having a meaningful light source at those other distances.

Don't forget the inverse-square rule!