This question applies to both fresh and dried mulberry leaves.

I first boil them for about 5 min to soften them up.

Then I put it in the tank.

Initially my Taiwan Bee shrimp pick at it, but their puny claws are too feeble, so they can't really make a dent and eventually leave.

Nobody touches it for the next day or two.

Day three it starts to turn yellow and go soft.  Occasionally a shrimp will pick at it, but not much.

Eventually it grows a clear / white fuzz on it.  Occasionally a shrimp will pick at it, but not much.

At what point should I just give up and take the leaf out?  It seems they're not really interested.

I haven't had fuzz ever on my leaves, though I only use dried naturally fallen and they are just put in the tank without boiling! As you state, they do take time to break down (weeks) but I assume biofilm grows on them and they must release some stuff into the water as they do break down, and I like the natural look!

None of this really helps you I know? The only times I get fuzz growing on wood etc is when starting/cycling a tank and that disappears with time as the tank sorts itself out!

Hope someone may be able to be more help.

Simon

 

I would take it out if it grows a white fuzz. 

I don't think it's harmful though

Thanks.  I think next time I will try boiling longer to soften the leaf more.