I made the below post on the Fruits forum in relation to acidification of water for blueberries. I thought I would repeat it here, as it could just as easily be used as a less expensive mode of fertilizer injection, or pH + fert mix injection. The injector is attached to my hose bib by a 5 ft hose, and a 1 gallon milk jug acts as my reservoir of dilute acid (for now, a more permanent and secure 5 gal bucket is in the works). Then, and 50 ft hose and a standard shower wand is attached as my distribution device. Just be aware, that changing the settings on a sprayer, or adding a second hose will add backpressure, and change the mix. It still works, but will need adjustment to maintain the same ratio. ____________________________________________________ I spent more than my budgeted amount on plants this year, so the addition of a fancy injector for acidification of water for lowering the pH of my irrigation water as out of the question. With almost 30 blueberry bushes, and living in a very dry climate (both low humidity, and very little rain), watering via buckets or watering cans, each treated to adjust pH was also not a viable option. My solution is a venturi device to pull acidified water into a stream of water and then distributed via a hose. Here is the second attempt to build a satisfactorily working injector. The first attempt was to use a ½ inch injector bought off ebay. Unfortunately, the smallest injector I could find on ebay required a flow rate that could not be delivered through a hose and hose end sprayer. Already on order was the Mazzei 283 in the picture above. Although still ½ inch threads, the injector is much smaller, and hence, designed to operate at much lower flows. I had to cut and mend the first attempted setup in order to fit the Mazzei, as the Mazzei was about an inch shorter. Hence the coupling next to the ball valve. This setup worked, but the ball valve left lots to be desired in the way of adjustment of the pressure differential on the two sides of the injector device. The injectors function is regulated by the amount of pressure differential between the input and the output, and the resulting flow rate. By opening the bypass ball valve, and letting pressure increase on the downstream side of the injector, less injected material is pulled into the stream at the venturi. Conversely, the injection rate can be increased by closing the valve, and increasing the pressure differential. I’m using 98% sulfuric acid, significantly diluted into a jug. This mixture, of which I’ve tried several concentration rates, ranged from 12 ml to 21 ml per gallon of water. This diluted mixture is then piped to the injector, and when a portion of this is mixed with the irrigation water, the overall resulting pH coming out the hose end is adjusted. As I said, the ability to precisely adjust the pH of the resulting water was lacking. And, if I wanted to use regular water, or less acidified water for fruit trees, or other uses, I would either have to pull off the hose and rearrange things, or open the ball valve all the way, and then readjust the pH through titration, and attempt to get the ball valve in just the right position. To address the adjustability, and add an additional bypass to simplify changeover to non-adjusted water, I built the following injector setup. Here is an exploded view of most of the parts, prior to assembly. I ended up adding a 200 mesh filter, as the secondary irrigation water here can be very dirty, and the orifice in the injector is small enough that it could get clogged. The use of a gate valve provides sufficient control, even if it still is not as precise as I would like it to be. I suppose one could use a needle valve for fine adjustments, but incorporating one wouldn't be as simple. And the additional ball valve allows me to simply open it to not inject acid, or close it to use the injection capabilities. The pH in my potting mix is a little high right now, so I’m adjusting the water coming out the end of my hose sprayer to a pH of 4.5 for the time being. After a few waterings, I’ll crack the gate valve open a little bit more (or I could add less sulfuric acid to the dilute I’m injecting), and put the pH closer to 5 or 5.5. I haven’t carefully tracked the costs of this setup, and I’ve spent extra in the various tinkering and rebuilds, but I think it is reasonable to say that one can be built for less than $50, presuming you already have tools and pvc cement. $60 if not. The injector is the most expensive part, about $30. A pvc gate valve is spendy, at about $7, which I found online, although some people say they can be found at their big box hardware stores. I suppose one could use a metal one, since it doesn’t come in direct contact with the acid, but I didn’t feel like dealing with any corrosion that could be possible. The rest can be obtained at any hardware store with a decent sprinkler component selection.

ya, You might try another forum on gardening, especially one that is stated for your area. There are many to choose from. They would have ideas about fertilization. You can also search older threads on using drip injector system. aloha

i have no experience personally with the ez flow product but i have read many reviews online that say it just doesn't work. as far as being expensive it is actually one of the cheapest available. seems like it would make more sense if you are feeding a lawn to use granular fertilizers applied to the lawn and then watered in. the injectors are used for drip irrigation mostly.

No, there was not obstruction. I think it's just that my flow is right at the bottom of the rating for that unit, 0.3 m3/hr, and they exaggerated. I think I may need to bite the bullet and buy a ridiculously expensive Mazzei unit that is rated for lower flow. $40 vs $5 for a piece of injection molded plastic.