How Do I Figure the Math To Use a Siphon?

Figuring the math to use a siphon seems difficult. There are ratios and tablespoons per gallon and ounces and cups, and how the heck do we figure out how much liquid fertilizer to use per gallon?

Actually, we don't need to do all that, we will use a magic number. It isn't hard because we are going to be working backwards, starting with what comes out the hose. Read on.

First there are a few siphon rules to follow. Don't use more than a 50 or 60-foot hose after the siphon (the siphon doesn't have to be located at the faucet), and don't put a restrictive nozzle on the business end. Make sure you have adequate water pressure and flow. These rules apply no matter what you do. Also, siphons are not real accurate; if you have to have a very controlled delivery look into a fertilizer injector.

OK, let's drop the siphon hose into a 5-gallon bucket, and let's use fish emulsion for our full-strength product, right out of the jug.

A 16:1 siphon mixes roughly ONE GALLON of bucket mix with every 16 gallons of water out the end of your hose. No matter what you're mixing, and no matter what the strength of your mix is, that's not going to change. Remember that 16, that's our magic number.

IF YOU WANT TO APPLY AT A RATE OF 1 TBSP PER GALLON:
16 gallons out the end of your hose at 1 TBSP per gallon would require 16 tablespoons of fish. 16 tablespoons converts to 8 ounces or 1 cup. Put that in the bucket, then add ONE GALLON OF WATER. We're done. Simple, huh.

IF YOU WANT TO APPLY AT A RATE OF 2 TBSP PER GALLON:
16 gallons out the end of your hose at 2 TBSP per gallon would require 32 tablespoons of fish. 32 tablespoons converts to 16 ounces or 2 cups. Put that in the bucket, then add ONE GALLON OF WATER.

How de we know when we've gotten 16 gallons out the end of the hose? The mix bucket will run dry and the hose will start to spit air.

Need more than 16 gallons out the end of your hose? Use the same number to multiply the number of gallons out of the end of the hose, the number of tablespoons of fish, and the number of GALLONS OF WATER to add to the mix. For instance, to make five times as much of that last 2 TBSP PER GALLON mix, multiply everything by 5.

16 X 5 = 80 gallons out of the end of the hose, for which we will need 32 X 5 = 160 tablespoons (which converts to 80 ounces or 10 cups) of fish. Put that in the bucket, then add 5 GALLONS OF WATER. That'll fill our bucket to the top. The easy way to do this, and this also charges the hose with the mixed solution, is to hook up the siphon and use the hose to fill the mixing bucket. What do we do to make it even easier? We don't measure, just glug about a half gallon of fish into the 5-gallon bucket and fill it up the rest of the way with the hose. That's about a 1 3/4 TBSP PER GALLON mix.

We go through a case of fish emulsion throughout the spring, spray it on everything until it drips down onto the soil. When the soil is cold, foliar feeding is a great shot in the arm for the young plants. Your garden crew (the good bugs and bacteria) appreciate any nutrients left behind on the leaf. And, at least for a day or so, the fishy smell confuses the insects homing in on plants with the intent of eating them.