I have a really bad problem with electrodes and I run a water type gym,so please can I have a Pokemon that can counter them.
Gastrodon. It's ground typing grants it an immunity to Electrode's STAB electric attacks, so unless it is carrying HP grass you will be able to wall it, especially if you are running a Stockpile set.
Water and Ground Types. Quagshire and Swampert both fit the bill. Personally, I would use Swampert in this case.
Well there are a few options, a very good counter would be water-ground types, their part ground type giving them immunity to electric attacks, and most can learn earthquake. But those are only a few options.
Seismitoad. Electrode is in NU, and so is Toad. Seismitoad can use it's Substitute set to set up on Electrode, or before (It carries Taunt), and use Earth Power. Electrodes switch out anyways, so I recommend using Rain Dance while they switch.