When you filter you should always have the syrup at or above 180, I think 190+ is better. I actually heat mine to 205-210 then filter. That way you have removed more niter, and you are less likely to get more building up if you reheat to 185 to bottle. Remember, the niter is basically the excess minerals (mostly) that precipitated from suspension as the syrup became saturated at that density.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.