Growing a Hydroponic Garden Without a pH or EC meter

So you have decided you want to start a hydroponic garden but you do not want to use a pH or an EC meter. It is fairly common for people to feel this way when they are starting their own hydroponic gardening due to several reasons. Maybe you are not very familiar with the technical side of hydroponics, you don’t want to get into all that stuff in the beggining or perhaps pH/EC meters are terribly hard to get or expensive where you live. Does this mean that without a pH and EC meter you won’t be able to run a successful hydroponic venture ? No. On today’s post I am going to talk to you about how you can grow hydroponic crops without a pH or EC meter and yet get good results, sometimes even better than people using all those technical gizmos :o).

As a chemist I think like a scientist and part of this way of thinking is the controlling of variables. I like to control pH and EC because I feel that this allows me to have a record of what is happening within my nutrient solution, without these measurements I would be “blind”, so to speak. However when I was beginning my major I started my first hydroponic ventures with absolutely no control over pH or EC. I didn’t do this because the cost of an EC/pH meter where I lived was prohibitive so I said, “what the hell” and went for it. I have to say that I got some very satisfying tomato crops after having some significant failures due to both rookie mistakes and disease. I managed to get full, 2 meter high tomato plants filled with delicious vibrant tomatoes and this happened without ever checking my pH or EC.

How did I manage to do this ? After time went by and I got an EC/pH meter, I started to monitor how my crop evolved with time to know what I should or should not do to improve my corp’s yields. I found out that the pH of my crop increased steadily – and sometimes came near 8 – before I usually changed my nutrient solution. The EC oscillated widely but my reposition of the initial “level” of solution with water was enough to keep the EC at a good level. So if you want to be successful with hydroponic crops, it is not absolutely vital for you to have a pH or an EC meter, you just need to follow some simple guidelines to have a wonderful hydroponic crop.

1. Have one gallon of nutrient solution per plant. Having this volume of solution in your reservoir per plants allows you to have enough nutrients so that each plant will take a significant amount of time to absorb them. Having less solution is troublesome since your EC will change wildly and your nutrient solution changes will have to be more frequent. A one gallon per plant rule of thumb seems to be the best choice.

2. Add fresh water to recover the initial level of your solution . This is one of the easiest things to do. By adding fresh water -without any nutrients- to top off your reservoir to its initial level you will keep the EC near its initial value for the whole time. This simple technique ensures that your EC remains within rational levels and your plants stress-free.

3. Change your solution every 4 weeks. After 4 weeks, in a hydroponics system where there is one gallon per plant and the solution is continuously topped off (at least once a day) you will find that your plants have used about 40% of the nutrients at most (this is what I got from full production tomato plants and an atomic emission analysis of the nutrient solution). This means that your solution is now deprived of nutrients and it is time to use the solution to water your soil-garden and prepare everything again.

With this simple guidelines, anyone will be able to grow a hydroponic garden without using a pH or an EC meter. Of course, in the beginning you may find some problems while you find the adequate level of nutrients your plants need (if you do not prepare them yourself) but after a few trial and error runs you will be able to grow full hydroponics gardens without having to constantly monitor either pH or EC. Certainly, better results are achievable when you are monitoring these variables but it is possible to grow a beautiful hydroponics crop without the slightest monitoring of these aspects of a hydroponic nutrient solutions. People usually underestimate the ability of plants to adapt to changing conditions, something that they are able to do beautifully if you only follow the above advice. Do you have any advice or suggestions to help people grow without an EC or pH meter ? Feel free to leave a comment :o)



  • LoLa
    June 6, 2010 @ 6:00 am

    Thank you very much for posting this. I am just about to start my first homemade outdoor DWC for tomatoes and don't want to spend too much and too soon. You are giving me hope.


  • Daniel
    June 6, 2010 @ 11:17 am

    Hello Lola,

    Thank you very much for your comment :o) Definitely you can have a lot of success without having a very "technical" approach by following the guidelines I have suggested. Having an excellent hydroponic crop is indeed possible without ever taking a pH measurement, some simple rules of thumb are good enough in many cases. Thank you very much again for your comment !

    Best Regards,


  • JT
    July 28, 2010 @ 5:57 pm

    I have a swimming pool and use a "kit" to test chlorine, PH, etc. of the water. Is it practical to use the same PH test for hydroponics? or is it a different type of measurement?

  • February 4, 2011 @ 4:21 am

    Hi Daniel
    What a great article. Many thanks. I’m a retired human physiologist just starting out with hydroponic cherry tomatoes, peppers & cukes. I’m using an 8 litre, clear plastic tank per plant, and needed some quantitative info as to how often to drain and replenish the nutrient solution. That 40% consumption after 4 weeks, for a nutrient volume of 1 gallon per plant, gave me all the info I needed.
    I use clear plastic tanks because there is pleasure in being able to see the root system develop and to see the airstones bubbling. It’s also easier to maintain fluid level without a sight glass or float. To prevent algal growth, I add a forceps tip (estimated at a ‘few mg’) of copper sulphate (Bluestone) to each tank of fresh nutrient. Copper, as you will know, is one of the most powerful algaecides, and I also use it in my swimming pool at a dose of approx 250 grams/50,000 litres. Magic. As for toxicity, copper uptake by plants is selective and, according to an article I recently read, it does not appear to increase proportionately with increase in copper concentration in the nutrient solution. (The US Environment Protection Agency specifies a maximum contaminant level for copper, in water, of 1.3 ppm, which works out at 1.3 mg/litre)
    Regards and thanks again

  • […] essential for the hobbyist. Here’s the article, which I found most impressive and convincing: As an aside, I’m aghast by the number of hydroponics websites which refer to pH as […]

  • […] Replenishment of nutrient solution This is a contentious issue. Most hydroponic enthusiasts change their solutions weekly or fortnightly (I have chosen the latter), but one author (Daniel Fernandez, a chemist) recommends changing the solution every month, provided that total volume of nutrient solution is equal to, or greater than, one gallon per plant. He writes ‘…..after 4 weeks, in a hydroponics system where there is one gallon per plant and the solution is continuously topped off (at least once a day) you will find that your plants have used about 40% of the nutrients at most (this is what I got from full production tomato plants and an atomic emission analysis of the nutrient solution)…..’ The article also states that, while a pH meter and EC (electrical conductivity) meter are very useful in hydroponics, they are by no means essential for the hobbyist. Here’s the article, which I found most useful and convincing: […]

  • Maja
    April 9, 2014 @ 9:50 am

    What about recirculating systems? Could it be also so simple?

  • Almero Cloete
    May 2, 2014 @ 8:55 am

    Daniel, I am a latecomer to Hydroponics – but I still made it at the age of 72!
    May I congratulate you on your blog and the scientific info that you graciously share with the world.

    I am from South Africa and spent my worklife amongst poor rural communities. I have started playing with aquaponics in my backyard in a barrel system. However, I now want to see if one can put together a very simple and unsophisticated hydroponic system which you can make available to poor rural communities where there is no electricity.

    When I googled “hydroponics without EC meter” it took me straight to your blog where I read that wonderful article. I also came across the old book written by Dudley Harris “Hydroponics: The complete guide to gardening without soil”. I read a few pages of the book on Amazon and read about using a smallish container filled with a medium such as coarse sand for each plant, and then pour the nutrient onto the surface of the sand from where the nutrient trickles down to the bottom where iit flows out into a bucket and is collected for re-use the next day. Apparently Harris got exellent result with this very unsophisticated system.

    Can you perhaps elaborate on such a basic system that could be helpful in the context of both urban and rural communities to help them grow some of the food they need to survive?


  • Salman
    November 23, 2020 @ 1:10 am


    Can you tell me how much NPK with Trace element you used in 1 gallon of water?

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