I made the conduit housing & placed the conduit in Survival mode at a sunken temple reading on online that it would hurt the guardians around it when it came apparent that the guardians weren't getting hurt at all. I moved away from the sunken temple & when into creative mode to remake the conduit housing shown in 2020-07-01_00.21.09.png using a combination of prismarine, Dark prismarine, prismarine brick & sea lanterns using the max amount of blocks get the conduit to full power. I used drowned spawn eggs to spawn drowned around the conduit to see if it was just the guardians that were the problem but it doesn't hurt the drowned either as shown in the other six .png scrren shots that I took in rapid succession to show that it's not hurting the drowned.

Update.
I made a video but the file size is too big.