[bonfire09]

it has to do with ksp. Na dissolves much more than potassium thus having greater electrical conductivity

[cheese (MSW)]

bonfire09: First let me welcome you to forum.  I am relatively new to this forum, but I have a piece of advice for you (and some others).   Please don’t BS (no easy way of putting it).  Some will see right through it.  Furthermore, there are anonymous posters who will quickly reward you with a –ve “mole snack” even when your answer is correct ( ).
Turning to your answer: if, as I hope, you have read the previous posts for this question we have established that for most  solns of sodium and potassium salts in low, equimolar concs the sodium salts have the lower electrical conductivity.  This is consistent with the view that Na(aq)^+ is  larger than K(aq)^+.  The exception is the hydroxides where KOH soln (low conc) has a lower conductivity than a corresponding soln of NaOH.
As you should know, all the common salts of Na^+ and K^+ are soluble in H2O. To attempt to explain this observation using Ksp values for such cmpds is therefore nonsensical.