It’s the hydroponic fertilizers that you add to your water to make hydroponic nutrient solutions!
The very best hydroponic fertilizers are the ones that are soluble and contain all the necessary nutrients for your plants. They should also not leave behind any impure residues as this will cause extra work for you when it comes to changing the solution. The best hydroponic fertilizers are manufactured using food-grade nutrients in the formula.
You can buy your hydroponic fertilizers in either one or two-part formulations. Many hydroponic gardeners prefer the simplicity of a one-part formula, as all you need to do is add it to the water therefore they are more simple to use. The two-part formulations tend to separate the macronutrients from the micronutrients. The advantage of the two-part formulations is that you have that little bit more control over what you’re adding to the mix. Depending on what you’re growing, this could be an advantage.
If you’re in any doubt as to the best type of fertilizer to use then the best thing to do is to consult with your local hydroponic store, otherwise simply look online for the answers. This very site is a good place to start regarding optimum levels of pH for what you’re growing.
Adjusting Hydroponic Nutrient Solution – pH Up Or pH Down
Since i’ve already touched on this, i’ll be very brief to finish this article. You need to check the pH of your hydroponic nutrient solution at least every other day.
If your hydroponic nutrient solution has drifted downwards, then you’ll need to add pH up. pH up is usually potassium hydroxide. Likewise if it’s drifted upwards then you’ll need to add pH down, which is either nitric acid or phosphoric acid. Always make sure you give the mixture a good stir after adding either up or down, leave an hour and then check the pH level once again to ensure it’s within the desired range.
You may have read in a couple of places that you can use vinegar to act as pH down or baking soda to act as pH up. This is not a good idea as this can cause algae and fungus growth. You may also end up with hard to clean residues when you do your weekly or fortnightly clean. In addition, while citric acid to act as down may kill one type of bad bacteria, you’ll be trading it in for another type of bad bacteria which thrives on the stuff. Although some people may disagree, my advice would be to play it safe and to stick with the commercial mixes you can buy online or at your local hydroponics store.