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.

Swampsnaggs, Just to clarify, the 70 trees in my orchard are all espaliers and are 6-7 feet tall so it is not like spraying a normal 70 tree orchard. I don't have to spray into a canopy and I spray from a relatively close range. When I spray it is almost like painting a wall with those paint sprayers. My reason for looking at the high pressure sprayer is because it can be adjusted to almost a mist/atomizer. My thought was that the mist would provide better coverage and more easily get into the nooks and crannies. At different times I spray with Captan, Imidan, Kocide, and others which are water soluble. I do NOT use surround. I was wondering if these would damage a piston pump. I was wondering if the droplet size from the 40-70 PSI diaphragm sprayers are fine enough to do the "nooks & crannies" thing. I would still get the 200 PS model if the stuff I use does not damage the pump. Mike

Have had Solo 4 gal unit for about 5 years.. initially got it from Costco costing about $85 It has a side pump (arm pump) and is virtually maintenance free as long as you rinse it out; after you use it! Have seen parts in Lowes but only part I had to repurchase was a tip and once I accidentally stepped on the brass wand.. so I replaced that also. I use it to spray dormant oil on some apple trees i have & spray my Blue Spruce Trees with Mitacide in August. THen I have another hand held sprayer that I put my Poisonous Weed killer and oil products in. I keep my sprayer uses separated as to not to make a mistake with my weed killers on my lawn. Some Weedkillers are SAFE for lawn use.. Some aren't. The NON selective ones like Roundup & Brush killer go in the small tank sprayer only. Well, thats just the way I do things..JMHO

btw... did your roundup have 'sticker'???? aka spreader???? trees are trees .... in my drought.. i have a lot of trees already shedding leaves .... and some color change.. not from temps.. but drought stress ... so i was thinking that a quick loss of leaves/needles.. would reduce any potential impact ... its gotta be that time of year when the leaves are shutting down ... i would like to hear what other tree 'spert think along those lines ... CHEAP CARP ALERT: for me.. the key with roundup is LOW PRESSURE... so i am now wondering how much pressure you put your tank under.. for it to explode .... care to fess up in that regard??. .... lol .. did you hook it up to the compressor and zoom it up to 100 psi???? .. END OF ALERT ... say a prayer.. make a sacrifice ... what more can you do??? again .... unless you had significant coverage.. i just cant think it will be impacted ... i have sprayed 2 year old, 2 foot, 5 leaf oaks... and the leaves die.. and the trees just keep coming back .... i have to cut them to the ground and apply 100% to the cambian .. to really do the job [that would e fer sure 100% contact].. though that is presuming your plants are otherwise established and healthy ... ken