Looking for chemigation system

Hi,
Another newbie in need of help!  

I have a 4ft x 8ft raised bed SFG and a few large planters that I irrigate with a drip irrigation system. My irrigation system is connected to a typical back yard water faucet that's fed by the local water company. Faucet pressure is 60 lbs at the bib but I reduce it to 15 lbs by using a 15 lb pressure regulator. Plants are watered with 1/2 inch tubing that feeds 1/4 inch drip tubing and a few 1 gph drippers.

I'm trying to figure out how to add liquid fertilizer, fungicides, etc, to the system so when it is watering my plants the liquid fertilizer, etc gets added to the water. I've seen several different venturi systems and chemigation systems with small tanks. Prices range from $15 to $500 plus. My garden is small so I don't need anything big.


My wish list:

1. I need something that will work with the low flow rate and 15 lbs of pressure my drip system uses. 
2. I need to be able to adjust the mix ratio so I can control how much liquid chemical get mixed with the water.
3. I have a small garden so I don't need something designed to fertilize/irrigate an acre.

Anyone have any recommendations? Ideas?

Any help is greatly appreciated!

Hi Johnmcc. Welcome from Atlanta, GA! Glad you've found us...

I use a 33-gallon tank to water my plants. It's just gravity fed. So I can't help you on your questions... But I'm sure someone will pop in & help you out!

Hi Johnmcc.  Welcome to the Forum from California!  

Your question is unusual for this Forum in that we primarily use 5-source compost as fertilizer, that is, to feed the plants.  The All New Square Foot Garden method, developed by Mel Bartholomew, uses only quality compost, vermiculite and fluffed peat moss.  No dirt.  All of the plant's need are within the 6" of mix.  For heavy feeders, additional compost or organic fertilizers may be added later in the season.  But, only when the plant indicates it needs these.  Therefore, a "chemigation" system is not needed.  My regular irrigation system has an inline fixture for adding fertilizer tablets but have never used it in 20+ years.

Chemical fertilizers are hard on the micro- and macro- organisms that live in the soil/mix that help convert the nutrients into usable forms for the plants.  Fungicides kill the fungi in the soil.  We love fungi in the soil!    Tiny arthropods, worms, good nematodes, bacteria and fungi all play a role in making a healthy soil.  "Teaming with Microbes" was a recent read for some members.

I hope you are able to find what you are looking for.  It seems Home Depot or Lowes should carry what you are looking for.

Actually, I'm not trying to add a fertilizer to my irrigation water. I just mentioned fertilizer in my post because that's what these systems are usually used for.

Reason I want to use chemigation is I'm trying to get rid of fungus gnats. I've been having problems with fungus gnats getting into the soil in my bed and planters and laying eggs. Doesn't take but a day or two and I've got thousands of them infesting my soil. For some reason the fungus gnats are very prolific where I live. (Little Elm, Tx)

So far, the best method I've found to get rid of them is to spray the adults with a pesticide to kill them. Then mix hydrogen peroxide with water and soak the soil with it. Hydrogen peroxide won't harm the adults but it kills the larvae. I was thinking about periodically adding hydrogen peroxide to the irrigation water to stop these bastards from breeding. I'd rather occasionally water with a little hydrogen peroxide than spray malathion/Seven everywhere.

Thank you for the clarification.  I did a quick search for control of fungus gnats and came up with 3 ideas.  Trapping adults with yellow sticky traps and spraying with BT (bacillis theringiensis) for larva control.  Neem oil mixed per instructions should kill the adults.  I also found recommendations of allowing the top 1-2" of soil to dry out.  Just use a spray bottle for application on the soil or on the plants.  I have several bottles I labeled for different solutions: milk, Dr. Bonner's liquid soap, Neem oil, vinegar (weeds), etc.