here is how mushrooms work.....mine THRIVE is the lowest flow area... and they don't like direct light either. i have a biocube with a crappy marine land fresh water LED, NOT for salt water and not the right colors and the mushrooms will get 4 inches tall and 5 inches wide, but in my big tank with $1000 worth of kessil LED's , and medium flow they wont hardly open. all the water is the same and is plumbed together so its only a light and flow issue.
i thought that i couldn't keep mushrooms for a year and realized i had too much flow in my tank. if they don't get enough light they will inflate and reach up toward the light to feed themselves. id put it where its shielded from flow behind a rock or something and make sure its not in direct light.. seem to do best on the bottom of my tank towards the side and back.. or really high in the back corners are even better unless you have a strip light. i have kessil can led lights so its shaded in the back top corner and my green mushrooms LOVE it..
leave it in each spot for at least a week before you move it again... it takes a couple days for them to adjust.... also keep in mind that those might have been raised under lower or brighter light if aqua cultured so this changed the relative measurements of what is considered bright light i guess..
