Reef safe ceramic magnets

[Halal Hotdog]

Hey guys, I have 100 of these magnets and wanted to start using them for reef purposes. Do they are ceramic magnets with no rubber or silicone covering. Are they safe to be placed straight in salt water?

https://www.amazon.com/gp/aw/d/B018ITTFDM/ref=cm_cr_arp_mb_bdcrb_top?ie=UTF8

 

[John3]

I don’t think so. It says they are made of strontium and iron oxide. I have been wondering if anyone makes rare earth magnets Incased in plastic.

 

[Rosenthalpotter]

Epoxy coated neodymium magnets. I buy them on eBay. Good prices