Just use a kitchen sponge, magnets can leave some pretty unsightly marks if gravel/sand gets in there. A quick wipe with the sponge side of a scourer will be better.
Hi,
The hc looks like its melting in places I've been dossing with carbo and ferts every day
I don't want to really go down the road of another co2 setup, anyway will see what it's like
At the weekend if it's bad I may be rescaping again lol