It's dummy here again, what do you mean "this time did not put the wires in the media ,instead I applies zapper
current from the top of the plate using 2 leads (screw like)."? Did the lead touch the media?
And what about normal zappers? Do we have to do it for longer?
yes it touched the media from the top through the cover plate.
as for normal zapping ,I meant if you have infection ,dont use your zappers one day and thats it. mayb you have to do it 2-3 days in a row or possibly longer ,agian this is my personal judgment.
Lab experiment # 3
Lab experiment # 3 
Brave heart
21 y
876
