i have a 1994 200zx and have a problem with the both livewells holding water,,,they fill fine with flip of switch and both aerate well too,,, but even with the "open/close" levers in "closed" position they dont "hold" water,,, is there an adjustment for the levers to "tighten" the closing power??? or are there o rings on a valve near each tank??? how do i get to them if thats the case?????????