Black suction cups reef safe? Alternate pump mounting method?

[Calm Blue Ocean]

A while back I was cleaning my skimmer pump and noticed black gunk on my hands. Turned out it was coming off the suction cups which were deteriorating. The pump was less than a year in the water. Fortunately the suction cups served no actual purpose since the pump was suspended in the skimmer body so I just removed them.

Fast forward to today, I just received two new pumps (different from the skimmer pump with the previous suction cup issue) for my mixing station and after rinsing everything in RO I went to mount one in my clean white 5g bucket using the supplied suction cups and they left black marks all over the inside of the bucket. As someone who is a bit paranoid about contamination in my fresh saltwater this did not sit well. I'm thinking I'll try soaking the suction cups in vinegar or citric acid in case it's just some sort of manufacturing residue but I'm not feeling super good about them.

Any cool ideas for mounting my pump to the bottom of the bucket without suction cups? Leaving it lose tends to result in the intake getting sucked to the side of the bucket. More and more I'm wanting to make my tank and mixing station suction cup free.

This is the pump I'm trying to mount:

NEWA Maxi power head

 

[Jedi1199]

I have never experienced "contamination" from suction cups in my tanks. The biggest problem with them, IME, is they dry out and no longer work after a few months. Magnets are the best way to go. I have seen an HUGE upswing in manufacturers abandoning the cups in favor of magnets.