Youngster, what concentration of sulphuric acid do you use? Or are you simply acidifying your water down to a ph of 5ish?
In my part of Southern California, our municipal water has a pH of 7.0-7.5
The sulfuric acid I use is the battery refill solution available from AutoZone, which is a 12% sulphuric acid solution, if I remember correctly. I use this to acidify the tap water, bringing it down to a pH range of 4.3 - 5.3, depending on the conditions and situation.
I have two sets of blueberry plants: 4 plants in 20-gallon pots and 10 plants in raised beds.
The blueberry plants in the pots are about 6 years old. I initially used a soil mix of half cactus soil and half peat moss. Now, the plants are a bit root-bound, and the soil is played-out. However, the blueberries don't seem to mind. I treat them similarly to how I grew weed in rockwool. Since the potted soil now lacks nutrients, I use a fertilizer solution with every watering, which is usually once a week for most of the year. The fertilizer solution varies, but it mainly consists of one part of a miracid-like fertilizer and one part ammonium sulfate pellets dissolved into a 50-gallon barrel on a caddy, for hand watering. I aim for a solution of about 100 - 700 ppm, depending on what I'm trying to achieve with the plants, typically staying within the range of 100-200 ppm. When aiming for higher ppm, I use more ammonium sulfate. I ensure to give them a good flush to prevent fertilizer salt buildup. With this approach, these plants are happy and productive.
The blueberries in the raised beds, also in a mix of half cactus soil and half peat moss, are watered using a direct inject system connected to a spigot to adjust the water's pH. I'm less precise with this system, and the pH usually ranges from 5.0 - 5.5, depending on how close I am to needing to change the injection tank, which holds 2 gallons of a highly acidic water/sulphuric acid solution. I run this irrigation system once a week and check the pH frequently. The injection tank typically lasts for a few months, but when it becomes too diluted, the pH suddenly rises. I don't use a fertilizer solution for these blueberries, as it would require adding a second injection tank to the system, which I prefer to avoid due to the added complexity and maintenance. This Spring, I fertilized the beds by broadcasting Espoma Holly-Tone Organic Granules and some sulfur pellets over the beds and mixing it into the bark mulch to distribute the fertilizer toward the soil surface. Despite not receiving regular fertilizer solution, these plants are also happy and productive.
I'd love to plant some BB directly into the ground but my adobe clay soil is daunting for this type of plant.