I use the dropper from my refractor, works great. Slowly approach the head while it's open and just before you touch it quickly squeeze all the vinegar out while still moving forward onto the little bastard.....poof all gone, next. Hit a couple at a time, don't try to take em all on at once look up vinegar doseing and use that table of instructions for a max amount to use in your tank as a daily amount. My system can handle 60oz a day so I have no need to worry, but yours may be smaller and only able to handle 4oz I dunno?