I have one plant out of 4 that has turned brown. It still has
cucumbers on it but very few new flowers. I see no bugs and the water
has been the same. Ideas? Should I replant?
MJ

There are several possibilities including plant stress, insufficient nutrients, or mosaic virus. You didn't say how close the plants are to each other or if they are competing for nutrients and space, so it's hard to tell. Did the leaves go spotted first and then brown? If they did it may very well be mosaic virus, in which case you should remove the plant as it has the potential to infect the others.