looks like your moving too fast on the aluminum if those black spots are porosity. either cup angle or gas flow is not keepings the air out of your arc.
definately wire wheel your welds before asking people about them.
anti spatter spray might help a little.
Really clean prep work and fit up make up half of the job of welding.
Not on your TIG welds. Soot **** and color of the weld beads are tell tail signs. Do that in any welding school with instructors that care about your education and you will be made to do the welds again.
Black soot **** is most likely contaminated tungsten with newbies, unsteady hands dip the tip

but contamination in the weld could be the problem as well.
Brown/red rust soot with steel black on aluminum with porosity, lack of shielding gas or air is mixing in with the shielding gas somewhere and/or contamination. Take apart and check your TIG torch over, check o-rings where needed and make sure hose fittings are tight. Also make sure your collet is in the right way this is a common screw up.
Color on stainless beads is lack of shielding gas after the weld puddle while its cooling and/or your weld zone is too hot. Dull sugary burnt weld, lack of shielding gas or simply just way too hot. On aluminum dull weld beads means your weld got too hot, you want your aluminum TIG weld beads nice and shiny, without anything wire brushing or polishing.
With antisplatter you shouldn't need it with stick welding. If you do, you are most likely doing something wrong. Too long of arc length, too much heat, current, lack of shielding, or contamination. Any splatter should come off with ease.