They have fertigation systems to mix solutions(vinegar,fertilizer,etc) with water at the proper ratio. Look it up. Battery acid, are you joking me? You would kill your plant, soil, and damn near anything it touches. Don't use battery acid, it's extremely caustic! Healthy soil, given plenty organic matter should buffer pH to some degree. I seen blueberries growing right next to vegetables, thriving. So make sure you take care of your soil, add a inch or two of compost and mulch(leaves,straw,etc) annually. Some blueberry growers use sulfuric acid, which is in batteries, to lower pH. I would not mess with it at home, it will eat right through you. Most use sulfur to lower pH. Though, i did hear Dr.Ignham talk down on it, saying it's a fungicide.. Here's a discussion on it. Here is a link that might be useful: Battery acid, blueberries?

Bamboo, thanks very much for the advice, but I wouldn't say I even have a problem to correct. I'm mainly just wanting to just deepen my understanding, particularly of non-purchased options for soil acidification, and in any case, dollar costs really aren't my concern at all. Not to hijack my own thread and make it too much about my own personal circumstances (as opposed to the more general questions), but I'm very satisfied with how my rabbiteyes are doing, and if the pH isn't in the ideal range for them, it's very close, and so long as they keep performing as well as they have been I probably won't even bother to check. I will probably check before I buy any more highbush plants. (I did receive two northern highbush plants randomly several years ago, and they didn't survive, but a number of factors, including transplanting due to a move, could have played into that.) Also, although I watered a fair bit the first year or two, I don't hardly water my blueberries at all any more. I may have only watered them two or three times this past year (albeit an overall wet growing season.) If bicarbonates were a problem, I could easily use rainwater for all my blueberry watering, but as little as I've been watering I don't know if it would even matter. What about coffee grounds, though, even if not for the purpose of acidification? Would it be good just to put them around the plants like mulch? Can I overdo it?

After reading all the comments, it’s funny that some of you act like, as if, sulfuric acid (battery acid) is a radioactive chemical, such as Plutonium. I've worked with battery acid and have gotten in my eyes at one time. It didn't feel good, but I ran to the next room and flushed them with sink water for 15 minutes. My eyes are just fine and that happened 30 years ago. If you get it on your skin, then rise immediately or it will start to burn your skin. Other than that, it’s more dangerous when charging the fluid that release toxic fumes and flammable H+ gases. I don't think you'll be doing that when using battery acid for watering your plants. I don't know if you can use literally battery acid, it may have other stuff in it, such as lead and etc. also, if you do use it, make sure the battery is charged at its full complicity before using it. You don't want to use a dead battery's electrolytes fluids. I'm not a wizard on this stuff, but I would recommend buying 100% or 98% sulfuric acid or h2s04 (brand new) in a bottle and not from a battery. To further explain my accident of how the battery acid got into my eyes, (not sure how or why), the container that I opened was under pressure when I opened it, it splashed into my eyes from the 'vent tube'. I think I may have opened it the other day, which allowed air to get inside the container, which reacted to the battery acid overnight and built up pressure within the container. I think that is what happened, but I'm not sure. Maybe I was squeezing the container to remove the cap or lid or held the container wrong, which allowed fluid to flow into the vent tube. My point here is that battery acid is not as dangerous, as one makes it out to be. Just don't drink it. Now, if you get it into your eye (out in the middle of nowhere), and you have no water to flush your eyes, then you can kiss your eyeballs goodbye. Skin will heal, but not eyeballs. Just make sure you have access to plenty of water, before playing around with acid. Make sure, the water is only no more that a room away from you. When I got acid in my eyes, it was not easy to see where I was going. I wanted to keep them closed shut, but I had to open them for a billionth of a second to see where I was going without running into walls. Note: The battery acid that got in to my eyes was brand new and may have been diluted with water. I'm 46 years old now, and I have no eye problem nor do I wear glasses. If you do the math, I was about 15 years old when this happened to me. Cooking foods in hot grease is just as dangerous as a bottle of sulfuric acid.

I grow blueberries both in the ground in raised beds (5 plants in the ground for five years) and in sturdy black plastic plant containers (5 plants in 4 to 7 gallon containers)--that I picked up cheap from a local nursery. Two years ago, I harvested over four gallons of blueberries. Last summer the container plants were a bit of a bust as a late 90 plus heat wave after I'd cut the watering back resulted in the container plants having a very poor crop, but I still harvested nearly four gallons of berries from the plants in the raised beds. They are picked and put into gallon freezer bags and popped into the chest freezer. I don't even wash them, as I use no pesticides on them. I removed my clay soil in 2'x2'x15" deep sections and built the beds up to about six inches above ground level with a mix of 3 parts sphagnum peat moss, 1 part leaf compost my town produces, and 1 part of the clay topsoil. I reused the rest of the clay in another part of my garden. The container mix is simpler: 2 parts sphagnum peat, 1 part leaf compost. The beds have not needed additional soil or peat in five years. I mulch the beds with pine needles (not for the acidity as they don't actually contribute any, but for the fact they contain no weed seeds to speak of). I use bark mulch as a mulch in the containers--it stops squirrels from digging in them and weeds from growing. I use drip irrigation with city water at a pH of about 6.5 or so, and fertilize with Ammonium sulfate every spring, which also keeps the acidity level up. Fafard makes a sphagnum peat moss based acidic soil mix, so that's an option if you can get past the sphagnum peat moss issue. If you're only growing enough blueberries for you and your family, you are not really going to need a lot of the stuff. It's worth noting that for every person who thinks sphagnum peat moss is not a renewable resource, there's likely another who thinks the opposite is true. Here's what I know: In the US, our ubiquitous Canadian sphagnum peat moss comes from a country that has a lot of it and only harvests a small amount of it, and reseeds the harvested areas with ... sphagnum peat moss, which in the university greenhouse collection I help maintain grows quite quickly--I frequently have to cut it back to keep it from overwhelming our carnivorous plants that grow with it. In North American bogs, the moss grows several or more inches a year. The harvested bogs won't be replenished soon, but they aren't exactly turned into parking lots either. Then too, the harvesting process is not very carbon intensive in the scheme of things. You can read more about this perspective on the topic here: http://www.theecologist.org/blogs_and_comments/commentators/other_comments/1780209/the_truth_about_peat_moss.html and here: https://garden.org/urbangardening/?page=august_peat