The fireflies(speckles) can be reduced by changing light clamping. Usually the indirect light which defaults to 10. I will usually set it to 5. Note: this can and often does make the render darker. In very rare cases, you may need to set the direct. I usually start at 10 and go down from there. Default is 0 or no clamping. Many people start at 5 and go up or down from there.
