im not sure what the exact suggested PPFD is for loph. but someone here will know. you can use the PPFD heat map to calculate distance.
here heat map PPFD
also. cumulative light is what matters. so its not just how intense the light is and how far away, but how many hours a day it is running
i use the UF2000 to grow mature seedlings and a few adult cactus. the UF1000 is under $50 and should perform similarly, just covering less total space.
for germinating seeds, i use something similar to the light you linked to, but full spectrum "white light" and with slightly larger screw in style bulbs.
if you just want to sprout seeds, you can probably get away with the light linked.
If you have any desire to grow larger cactus. anything over a foot tall or 1" in diameter, i would strongly suggest spending the $50 for a legit LED panel grow light.
meh... kinda. for sprouting seeds. yes, probably. anything over an inch or so, they are going to be starvinv for light
for only $10 more , you can get a REAL light that can grow an actual adult san pedro. with rated lighting output charts provided.
i have two of the larger versions of this light. the UF2000 and UF3000. they are legit
Get a uf1000 , cheaper and mines been working great for the babies. Been using it about a year. UNIT FARM UF1000 Grow Light 4000K Full Spectrum LED Grow Light, 60W Seedling Grow Lamp for Indoor Plant, 2x2FT Microgreens Clones, 1x1FT Flowering Fruiting https://www.amazon.com/dp/B08JCD11P2?ref_=cm_sw_r_ud_dp_C2Y2KPFNQP0ZTG9DMHE1
I have a uf 2000 too, both in 2x4 grow tent
im not sure what the exact suggested PPFD is for loph. but someone here will know. you can use the PPFD heat map to calculate distance.
here heat map PPFD
also. cumulative light is what matters. so its not just how intense the light is and how far away, but how many hours a day it is running