Something else is causing the nitrate spike. How often do you clean your filters? Test your tap water for nitrates. Scoop out uneaten foods. When i was doing rays, i change my water every 2 days on a 225g tank.
Since this past winter, we had been hammered with lots of snow. I saw a 745i stuck on I95. I would say ill go with benz. never got stuck in the snow with it.