by Michael E. Basham
My question is about nutrient solution pH levels. I started my first hydroponic garden about six months ago. and I have had a moderate amount of success. One thing that I have yet to get settled in my mind is what method to use in measuring the pH levels in my various systems. Some sources say it is better to use test strips, while others say a moderately priced meter is the way to go. One con in regards to using a meter is the calibration solutions that must be used to keep it accurate. What method would you recommend for a home hobbyist?
Answer: Michael- for the home hobbyist, pH test strips are just fine for monitoring the nutrient solution pH. There are a number of reasons for this. First, the ideal range for the pH is around 6.2....this is the spot where the maximum number of primary, secondary, and micro-nutrients are available. However, when hydroponic gardening, many growers use a much lower pH. I personally have known growers who mix their nutrient solution up at 5.2-5.5 pH, and then let the pH of the solution slowly drift upwards over time. Be careful if you try to do this....some plants will not tolerate it!
On the other hand, many old-time soil gardeners swear by 7.0 as the pH you want to keep. This is mainly to benefit the beneficial micro-organisms in the soil, which in turn release humic acids, which in turn help to keep nutrients chemically available at a pH of 7.0. However, even in a hydroponic system, the vast majority of the nutrients are still available at a pH of 7.0 (even without humic acids present). I only say all of this to prove a point- pH test strips and pH drop indicator tests are both more than accurate enough to manage your nutrient solution pH effectively.
On the other hand, a good pH meter is more accurate. Even though it is expensive when you first purchase it, you never have to worry about buying pH test strips ever again. I owned a Milwaukee pH meter for the last 10 years....it is still just as accurate as the day I bought it, and I have never purchased any calibration solution.
The first thing you want to do to keep your meter accurate is to always keep it clean! Every time you test your nutrient solution pH, you should immediately rinse the probe with plain water. I used to keep a little calibration solution in the rubber cap of the probe, but this is not absolutely necessary. The second thing is, DON'T ever touch the glass or metal parts of the probe with your bare hands (or anything else, really)....the oils from your hands will affect the pH reading, and so will any scuffs or scratches on the glass part of the probe.
You should never need to buy calibration solution really. I did so a couple of times when I first got my pH meter, and it is a waste of money. Instead, I made sure the instrument was accurate when I first purchased it (they usually come with one packet of calibration solution), then I tested some room temperature tap water. Municipal water supplies are usually very consistent as far as pH is concerned. Simply remember what the pH of your tap water is supposed to be, and from time to time test the meter in a cup of room temperature tap water to be sure. Better yet, use distilled water!
Having done it both ways myself, I really have no preference. PH test
strips and drop kits are certainly more affordable. If you have multiple locations
that need the nutrient solution pH tested, this is another reason to go
with test strips or drop kits....it is very convenient to leave a bottle at each
location, just in case you forget your pH meter (or your batteries die).
Check the pH of your nutrient solution at least once every day. From time to time you will need to adjust the pH. This should only be done with high quality pH UP and pH DOWN products specifically made for hydroponic gardening. Add them a little at a time, mix the nutrient solution well, and retest the pH until it is OK. When maintaining your nutrient solution, always check and adjust the pH first. Check and adjust the nutrient solution strength last, because the addition any pH UP or pH DOWN will increase your nutrient solution strength.
I suppose when you take into consideration how much money you save NOT
having to buy food at the grocery store, it is surely cheaper to grow
your own food hydroponically even with the cost of high quality
nutrients. Nevertheless, I didn't have a whole lot of money to work with
and I needed to make my efforts as affordable and effective as
possible....and in the last 24 years I HAVE learned a thing or two!
As you browse through Jason's Indoor Guide, you will notice all of the systems that I use personally are homemade systems. As I got 3 or 4 years of experience under my belt, I quickly adopted a preference to standing water systems and systems that use expanded clay pellets or lava rock, because the media is re-usable and it eliminates a huge operating expense. So once a hydroponic system is built, garden maintenance is minimal- check and adjust the nutrient solution daily, and to change it completely every 2 weeks....and the biggest operating cost is the hydroponic nutrients. (and the electric bill, lol)...
And, regarding the cost of the nutrients....I experimented for about 3 years with making different compost teas and nutrient teas, but there is still a lot of expense $$$ associated with making high quality nutrient teas....like kelp meal, liquid seaweed, rock dust, bat guano, un-Sulfured molasses, worm castings. You can eliminate a lot of this expense by becoming an expert at making high-quality colloidal humus compost, and use your properly made compost as the basis of your hydroponic nutrient solution.
Unfortunately, I have been gardening for over 24 years and I have only
just recently mastered this difficult skill....and even then, only
because I happened to find a very easy to follow, high quality technique
and decided to follow the instructions to the letter. I produced more
high quality compost in just one week than I was able to use in a whole
year! If you can master the technique, I highly recommend it. It is one of the top 3 things you can do to
increase the productivity of your food production efforts, while at the
same time decreasing the amount of effort required to grow all of your
own food, and decreasing the total cost of operating your food
And when I say decrease operating costs, I mean decrease them to almost ZERO, especially if you are producing your own nutrients...
The ultimate solution to eliminate the cost of your hydroponic nutrients: Imagine a hydroponic system that does not require you to buy any nutrients, does not require you to make your own compost, and does not require you to brew your own nutrient tea. Seriously! No cost and no effort as far as providing nutrients to your plants! Plus, at the end of the gardening cycle you harvest all of your garden vegetables, PLUS YOU HARVEST FISH from the system--->
This solution is aquaponics. If you are serious about producing all of your own food and being self-sufficient, this is the ultimate solution for reducing expenses (as much as possible), reducing the total amount of work required, and maximizing the productivity of your gardening efforts. I have been gardening for over 24 years, and it is the perfect food production solution in my opinion.
Besides mastering how to make high quality compost, learning aquaponics is one of the top 3 things you can do to increase your garden productivity, reduce your total costs, and reduce your total work. The product that I learned from is called Aquaponics4you. With all of my hydroponic gardening experience, the first time I came across the Aquaponics4you product I knew immediately that it was something very special! Place an aquaponics system outdoors and use the sun instead of grow lights, and you have reduced every garden expense to nearly ZERO!
The Same System/ 10 Weeks Later!