Opening the holes in the spray bar will decrease the intensity of the current without reducing flow through the filter. Try making the holes only slightly bigger one size at a time until the current is where you like it.
I know, I know, drilling out the holes is irreversible, but it is better than decreasing the filtration. Those filters have a valve you can regulate flow with but again, you will be decreasing the filtration.
BTW, that is a LOT of filter for that tank...try using just one 2028 until the fish are bigger then add the other 2028?
Just my 2 cents.