Bill Smith Posted July 26, 2020 Share Posted July 26, 2020 (edited) Hi all: Thought I'd share yesterday afternoon's quick project. My Easy Green doser is based on a glass Starbucks coffee bottle, a USB nano pump, and a few parts I had lying around the house. Here's what's involved: 1. Starbucks bottle ($3): Glass is necessary for this kind of approach, because it doses the fertilizer based on air pressure. Plastic bottles flex too much!2. Digital timer ($7): Needs only to be accurate within one minute.3. Airline adapters ($0.25): for joining multiple lengths or air tubing.4. Airline adjuster valve ($2): Higher quality is somewhat important here; I recommend the Ziss valve.5. USB nano air pump ($9)6. Airline tubing ($1): I used three lengths, about 5 feet total. Total Cost: About $22-$23 After cleaning the bottle and removing the labels, I drilled two 3/16" holes in the metal lid. I glued the two airline adapters into the lid from the bottom using 5-minute epoxy. (Silicone would have been better, but I'm impatient!) Then, I attached a short length of tubing on the inside of one of the adapters, and two longer pieces on the outside. That's pretty much all the DIY work that's involved! As air is pumped into the bottle, the build-up of air pressure forces the Easy Green out. I installed the Ziss valve on the output end of the fertilizer, and cranked it down to almost closed. I tested this with water first. 😉 Knowing the following: - 20 drops = 1mL - The digital timer can only run in as little as 1-minute increments - It will continue to drip for a few seconds after the timer turns off ...I set my digital timer to one minute and plugged in the pump. I then turned the valve all the way down so that I was getting one drop about every two seconds. That works out to about 35-40 drops (about 2mL), which is a perfect one-time dose for my 20 gallons of water. Here's the whole rig ready to go: And here it is installed in my sump: There you go! It was less than $25 in parts, and less than an hour's worth of work. Thanks for reading! Bill Edited August 10, 2020 by Bill Smith 10 7 Link to comment Share on other sites More sharing options...
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