I've been trying to get my hydrangeas blue, but honestly haven't been putting in the needed effort and this season about half are coming in pink. I'm increasing my efforts though to change the pH of the soil and get a procedure in place this year that will hopefully show the needed change next year. I've been using soil acidifier and plan to use more over a larger area (especially near fence posts with concrete next to plants), but I recently realized my tap water is rather alkaline. So each time I water the plants, I am just undoing my progress. I had already been tempted to do a fertilizer injector on my drip irrigation, but now I am looking at using that method for injecting vinegar in to lower the pH of the water. I have an EZ-Flo on way for that.

So here is my question. My plan is to have the EZ-Flo filled with vinegar. Will it be ok for me to add miracle gro for acid loving plants to that? I don't know if the vinegar would affect the fertilizer and have some sort of chemical reaction that would either neutralize any benefit or cause a problem. Thoughts? Worst case I just continue what I'm doing and feed the plants with a watering can.

Thank you!