Fertilizer mixers / injectors recommendations

Like you I had used a siphon system for years. Then I asked our friend Marne to take a look at what I was doing to grow orchids. She tested what was coming out of the siphon and to my surprise I was dosing my orchids with about 1200 ppm at each watering . She suggested the Dosatron and I am now on my second unit. My experience has been that they are very reliable in delivering the level of fertilizer you deliver to your orchids. Incidentally their service people are very helpful and patient in helping you with any problems that you may have with the Dosatron. After fifteen yeas of use I can recommend the Dosatron

 

Raven,

I have always had Dosatron and Dosmatic injectors in my greenhouses (look at qcsupply.com for a good price), and there are Chinese knock-offs (knocks-off?) that some of my customers have found to be quite reliable and a great deal cheaper.

Now that I downsized my collection and grow on my deck most of the year, I simply use an Ortho Dial-and-Spray house end device, and was both cheap and reliable. In the greenhouse, where the fertilizer was metered into the RO water, I used the hose-end sprayer to add KelpMax and probiotics.

 

When I had a greenhouse with 750+ plants, the metering pump fed K-Lite at 25 ppm N for all waterings.

Now that I have a much smaller collection, when they are out on the deck, where they get watered 2-3 times a week, and they are fed once a week @ 100 ppm N.

When they are indoors, I water with a battery-powered sprayer 2 times a week, and that contains 50 ppm N solution.

 

Personally, I recommend Dosmatic (made in The US and can be serviced here, if need be) over Dosatron (France), although, having used both for decades, neither ever needed repair.

The portable setup Marni referred to was simply a steel hand truck to which the metering pump was mounted, and fed out of a 5-gallon bucket sitting on the lifting platform.

The unit I found most utility was the Dosmatic MiniDos 12-1%, which can handle 0.3 to 12 gallons per minute, and can be adjusted to inject at ratios as high as 1:100 or as low as 1:500.

A word about mixing ratios: do not be tempted to make the fertilizer concentrate too strong to give you more time between refills, as you’ll start running into precipitation issues. Greencare, for example, says the the solubility limit for the MSU fertilizers is about 2#/gallon, but that appears to be for material used right away or kept in an actively agitated stock tank. I found that half of that, or even less, is more stable.

I also found that instead of adjusting the pump for different feed ratios, based upon the product to be used, it was easier to pick a convenient ratio and leave it there, adjusting the tank concentration, instead. They aren’t the easiest things to adjust….

If you intend to use any organic materials like probiotics or KelpMax, or others with short lives after dilution, I recommend not using the metering pump to deliver them, but placing them in a hose-end sprayer on the fertilizer watering hose instead.

For example, let’s say you want to routinely feed K-Lite @ 25 ppm N. That requires 0.73 g of powder per gallon of final solution, so if you have your pump set to a 1:100 ratio, your stock tank will have to contain 73 g/gal or 0.8 pounds per 5/gallons, giving you 500 gallons of solution between refills. (That’s what I did.)