Bricks, Masonry, Asphalt and Concrete - Re-Pointing Brick w/ Color Mortar Blend

Something seems not quite right, after re-pointing 2 of 4 brick piers holdng up my front porch. The mortar is gritty & crumbly; although, I thought I had taken care to use the proper proportion 3:1 (sand:mortar). The sand was bagged from a reputable supplier, and I had made sure to tell them what the sand was going to be used with; i.e., colored mortar mix for re-pointing.

Was the sand grit too large, or was the proportion incorrect?

Thanks,

Erik

May be too much water. How thin was the mix?

I used care in getting the right consistency, and the mortar stuck to an inverted trowel; however, I didn't mention that I didn't use a mixer, but I did mix the sand:mortar mixture thoroughly. Themortarman recommended a "fine" grade sand for tuck-pointing. The supplier sold me the incorrect sand grade for the job, I think. After looking at the choices they suggested in a display case, I questioned them about a finer grade, and they told me it was used for slump testing, etc..; that was the stuff I likely should have used.

Thanks.