Choosing a Hydroponic Nutrient
Ready made, concentrated Hydroponic formula is available at specialty stores, on line retailers and recently most nurseries are stocking a wide selection. There are so many different solutions currently being produced that walking into a shop can be a bit intimidating. While it is true that there are a lot of different types & brands, your main concern for now is selecting a quality, proven and reliable formula. Research what you will need as much as possible and choose the most suitable, high quality, well known formula for your application before going to purchase from a retail store. While most employees at any given shop are knowledgeable, helpful and looking out for your best interest, I have met a few that have no idea what they are talking about, or are trying to either push an inferior product or sell you “the best” which is usually the most expensive. Your best bet is to find what you need beforehand and ask for it. Ignore everything else, and buy what you came for. Have you noticed the repeating keyword yet? “High quality”, can make a big difference.
The best choice and investment for beginners is to start with a three part system.
I highly recommend the General Hydroponics three part system Flora series for a high quality tested and proven formula. General Hydroponics has been around for a long time and are the most commonly used worldwide. General Hydroponics has recently added more variety to their selection, including FloraNova and they also produce bulk dry nutrient mixes.
Three part systems offer the advantage of being able to custom blend your solution for various crops and growth stages. The labeling on the package will include the standard N-P-K rating, representing the percentages of Nitrogen, Phosphorus and Potassium. Also, look for a guaranteed analysis. Mixing a three part system is pretty easy and directions should be provided. Always shake well before using. Most systems must be mixed in a special order and should never be mixed together without first diluting. This can cause nutrient lockout, making some minerals unavailable.
Always use a nutrient solution that is made for hydroponics. Standard fertilizers like Miracle Grow are not manufactured with the necessary minerals because they are made for use with soil, which already contains most micro nutrient.
Measuring nutrient concentration is done by testing electrical conductivity of a solution in parts per million (ppm) or total dissolved solids (TDS). Pure distilled water contains no conductive mineral salts (electrolytes). Most municipal tap water can read anywhere from 120-400 TDS. Anything above 500 is considered unfit for consumption. Just for fun you should measure yours, you may never want to use it again though. Pretty much all municipal tap water is unfit for any use other than washing in my opinion, but that's another story for another day.
A digital PPM meter is commonly available and easy to use. It must first be calibrated using a known PPM solution and can easily and conveniently measure your nutrient solution by simply submerging the probe into your solution.
Proper temperature of nutrient solution is important for a number of reasons. An optimal temperature to aim for is between 68-75º F. Cooler water can retain much more oxygen than warm water, and we have already discussed how important oxygen is for root development. Poorly oxygenated and exceedingly warm temperature do not mix well in a nutrient rich environment which is already a perfect breeding ground for all kinds of bad things. Bacteria and fungus are necessary for a balanced system, but there are some pretty nasty ones that can easily propagate and out compete, not only your plants for food, but beneficial bacteria as well.
The entire nutrient solution should be changed every two weeks at minimum. Over time your plants use the nutrients and deplete necessary, vital components. Adding more nutrient solution is not recommended and can lead to toxic levels of minerals. Different stages of plant development and size, as well as environmental factors, determine the amount of nutrient solution required for optimal growth. E.G. seedlings and cuttings only require a small amount of nutrient solution, while vigorous vegetative growth requires the most nutrient of all stages.
