It seems to me there are some do's and don'ts when feeding mackerel but I cannot remember. I am having a hard time finding water packed sardines around here. Fed the last can today. For those who feed mackerel can you share any tips you might have? Also amount per serving. With the sardines they each get a can. The mackerel I found is 15 ozs or maybe 16 when I went looking today. TIA