Yes more information would help. What material thickness are you welding. What amps. Your gas is too high. Bring it down to about 12 CFM. Pics would also help. They key to aliuminum is clean. Dedicated stainless toothbrush type. Then follow up with acetone. The other keys to alum. are fast and hot. If you are slow you will overheat the aluminum and cause that grainy looking weld. I like to get a puddle in less than 3 seconds when I hit the pedal and then move swiftly while dipping.
T.J.
Im going to disagree with your technique here. When you form a puddle really fast, you are applying a lot of heat to a concentrated area of your work piece. As you move forward you will have to adjust your amperage (Down) due to the heat traveling through the material. For beginer to moderate welders, this can be a difficult process to master.
I prefer to start my arc with low amps and let the heat travel throughout the work piece creating even heat before forming my puddle. This will allow me to keep a constant weld bead and not having to adjust my heat up or down. This is more difficult with thicker materials, but then pre heating is another option
