Depending what’s going on I’ll do a 4cup /1 packet of furan-2 dip. I’ve had best results following that with a 4 cup / 3 drops lugols dip. I use an air stone for circulation. If I’m dipping a bunch (I have a lot of strains so a few might be struggling at any one moment) I’ll make a fresh batch.
I’ve had poor results with Coral Rx and hydrogen peroxide dips are best reserved for frags with algae issues (IME peroxide dips at any concentration are harsh).