How To Clean A Filter

[annasmommy13]

So I have a 2nd hand filter, it has greyish white stuff gunked to it. We want to give it a good clean before using it and rid all the spots. Any suggestions? TIA

 

[Meeresstille]

Is it calcium deposits? Vinegar is supposed to be good for that, but you will still need to apply some good elbow grease! Just recently I found out about filter batting working sort of like steel wool on it without scratching the glass, but I've never tried it myself yet!

 

[annasmommy13]

I think that's what it is, going to try the vinegar! Thanks