I apologize, I thought you meant you sprayed PH Down or a solution of just water and PH Down on your plants. I shouldn't have said "incredibly stupid", it was 4:30am and I was upset about something else. Poor choice of words and I don't usually attack new growers who make mistakes. I sincerely apologize.
How much PH Down was in this solution? If you just PHed a whole heap of water and used it, it shouldn't be that bad. I adjust the ph of my water before using it for foliar feeding. I've never had any ill effects from doing this. But I don't foliar spray often, only cuttings that are rooting. I find that most of the time when people are foliar feeding, they are "over loving" their plants. It's more for the grower than the plants as they don't need it. The grower just feels the need to be doing something.
PH adjust the water that you feed them with (in the soil) and check the runoff from the pots every couple of weeks. If it gets a bit high feed with lower ph solution if it gets low, do the opposite. Should be all set and the plants should show new growth and be just fine.