How to Choose a Hydroponic Fertilizer
Hydroponics systems require a carefully crafted fertilizer, or nutrient solution, to grow optimally. If you are just starting out in hydroponics, or if you’re experiencing some issues with your current hydroponic production, this post will help you in deciding which nutrient solution is best for your system.
Two Considerations Before You Choose
Before you get too carried away, be sure to think about two different variables in the nutrient solution equation.
Whether you’re growing for fun or growing for profit, you’ll first want to consider both convenience and price when deciding on the appropriate fertilizer for your system.
As you’ll read below, hydroponic fertilizers come in two different forms: liquid and powered. If you’re a hobby grower just starting out, you probably want to go with something a little less hassle (i.e. a little harder to screw up) like a liquid solution. While this type of solution is a bit more expensive, don’t forget the value of your time and frankly your sanity. For commercial hydroponic growers, powdered forms offer better value in bulk quantities but take a bit more skill to perfect.
Don’t forget: everyone has a budget so be sure to keep a close eye on your nutrient costs as they can creep up on you over time if you’re not careful.
Hydroponic Nutrient Solutions: Liquid vs. Powdered
As mentioned above, hydroponic nutrients are sold either as a premixed liquid solution or a solid powdered form.
Liquid nutrients are more commonly used for hobby systems as they make adding fertilizer quick and easy. For example, we send out liquid nutrient solution for our Spring Systems, as most Spring owners don’t have the time or resources to mix up a powder fertilizer. We’ve seen the most success with Dyna Gro Foliage Pro, a premixed liquid fertilizer with a 3-1-2 NPK ratio. For this reason, it’s the solution we trust to get our beginner hydroponic growers off to a good start.
Solid fertilizers typically are sold as a two-part powder mix. The first part is calcium nitrate and the second is the main nutrient mix. If you are using choose a powder mix, you want to make sure you mix the two powders separately and then add them together as a solution. (The reason for this has to do with calcium nitrate being a poor team player when dissolving; it dissolves better when mixed on it’s own. Once it’s dissolved in water, it can be added to the main nutrient solution.) Most of these two-part mixes are complete solutions, but a few will require another compound (such as magnesium sulfate – a.k.a. epsom salt) to be added as well.
Although powdered fertilizers are more complicated to use than liquid solutions, there is a big benefit in price. Since nutrient solutions are mostly water (only a few teaspoons of powder are used per gallon of water), shipping large quantities of solution is extremely expensive (i.e. you end up shipping a lot of water weight). Larger hydroponics systems usually use powdered mixes because you don’t have to pay for the weight of the water in shipping costs. Another plus is that you can get powdered mixes specific to different crops- a strawberry mix, a lettuce mix, etc. (although this can also be true of liquid solutions). Hydro Gardens sells a variety of formulations of fertilizer.
When to Add Nutrients to Your System
If you are growing in a Spring System, adding nutrient solutions is easy- six tablespoons of Dyna Gro when you start the system and then new water with Dyna Gro each time you replant. We designed the Spring for ease of use, minimal work and maximum returns.
Knowing when to add solution to larger hydro systems, however, is a little more tricky. You’ll want to be taking two measurements on a fairly regular basis: pH and EC.
A measure of EC (electrical conductivity) will tell you when your system is running low on nutrients. EC is essentially a measure of the salts -and therefore the nutrients- present in the solution. EC should be between 1200-1500 parts per million, but this number depends both on the crop and water demand. The best way to decide where to set your EC threshold is research! (Get a book on hydroponics – We like this one)
Another thing that is crucial when adding solution is pH regulation. pH dictates the “usability” of the nutrients by plants and microbes.
How often should you check your system? If you are hand dosing your system (testing the water yourself), you will want to check it once or twice a day. The more convenient option is to buy a dosing system- a computer with sensors and pumps hooked up to solution which tests the water in your sump tank for you (every 5 or 10 seconds) and corrects it automatically. One such dosing system is Autogrow’s IntelliDose.
We’ll be discussing more on EC and pH in future posts so stay tuned.
So what are the best hydroponic nutrients for you system?
Hopefully this post has helped you in choosing the right nutrients for you.
Remember, before you go out and buy any old solution, there are a few things to keep in mind.
You’ll first need to decide whether you’re leaning towards convenience or price. Are you willing to spend more on less hassle and potentially fewer mishaps? Or are you looking to save costs and experiment with mixing your own.
There are several incredible resources out there on hydroponic nutrients, and we will be outlining more hydroponics 101 tips and tricks for optimal growing in the near future. As always, we provide free resources for growers like you so that you can have a successful system.