Do you provide seaweed for your Tangs 24/7?

[Coasting]

Ive only had my 2 tangs for a few months but neither have ever touched seaweed when ive offered either on a clip or tied to a rock. Evem tried a few brands and what not. The Anthias end up eating it when it falls apart by the next day. They both graze off the glass and rocks all day however.