yellow slightly mouldy leaves

Hi, I recently watered my hedera helix glacier for the first time this year, with some liquid pour miracle grow that was added to some water. Since then I've noticed an increase in yellow and brown leaves on of the ivy plants. Some of the yellow leaves look mouldy too.

Does anyone know why this has happened? and should I cut off the affected leaves?

Thanks

 

I think, this is happened because of the liquid pour miracle grow that you have added to the water!!