Great white sharks. Trophic Pyramid Information that is in video: An ecological pyramid (also trophic pyramid, energy pyramid, or sometimes food pyramid) is a graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem.
The risk is that you may not be able to remove all the acid and if it is left on the metal it will continue to corrode the metal. So to give you a quick answer, you can use vinegar to etch the aluminum, but you have to rinse the surface thoroughly to remove all the acid residue.
1 White vinegar, a weak acid, is about 5 percent acetic acid. It may remove hard water deposits from glass, rust stains from sinks, and tarnish from brass and copper. 2  Lemon juice, another weak acid, contains citric acid, which can be used in much the same way as vinegar.  Oxalic acid is effective as a rust remover.