Is this felt pad fish safe?

[FishNCash]

I saw these at Walmart and Michaels. It’s 100% polyester felt and come in different sizes. I was wondering if it’s fish safe for my sump as mechanical filtration. Has anyone used it or know it is fish safe?

http://www.michaels.com/white-felt-...MI14zojZfZ2wIVGMZkCh1HXQj-EAQYASABEgIpf_D_BwE

 

[esoxlucius]

They're ok. I've used similar in the past, i think I might still have some actually. The only downside for me using those type of pads is that they are very very fine and clog quickly. I was changing them every other day and got a bit fed up of it. I prefer to do my maintainance once a week! But you might get more mileage out of them depending on your set up.