I'm wondering how much does water ph level matter for plant healthy growth as an aquaponic system would presumably have one ph level for all growing plants and as far as I understand and find on the Internet, different plants have different preferences for their root environment ph levels.

So, how does having a "flat" ph level for all growing plants impact their growth and health?

Does it make sense to create separate aquaponic systems and organize them by growing plants ph requirements?

Thank you in advance!

1 Answer 1


This is a great question Georgi! I am learning about aquaponics and hydroponics so there will be far better answers. Aquaponics deals with the addition of fish, hydroponics is what you are doing, yes? That would make a difference with pH or rather testing and choosing a pH that would work for both your plant selections and the fish.

pH is a major deal for plants (not to mention aquariums and hot tubs). For instance, potatoes love a lower pH than one would think. Most plants thrive at a neutral 7.0 or 6.5 pH. Potatoes need at least a point lower.

One of the major differences between those that are great growers of plants and the rest is knowing the pH preference, needs, of the crops one is growing. For hydroponics that would entail a few 'beds' parallel versus in series to allow for differing pH needs. Hey I am just guessing, grins.

One of the best sources for hydroponics is Jorge Cervante's Cannabis Encyclopedia. Truly one of the best most detailed right down to the nitty gritty chemistry, technology and botany. Only one plant is the star in this book which actually makes the information more understandable and usable. Cannabis loves a bit more alkaline pH. Growing this plant in 6.5 pH makes for a very wimpy plant. Raising the pH to slightly above 7.0 is best for this particular plant. pH is very very important. Anything you can do to be on top of all your plant's needs will be critical in such an artificial system. I am glad you are thinking about pH!!

Gotta get some pH testers...and I'd get at least 2 different ways for testing to check results. Feel free to correct anything I've said that is questionable?

  • Thanks @stormy, I'm planning a hybrid system of aquaponics and aeroponics (for the plants that yield better results that way) and I was thinking of using one fish pond for the whole system but if ph significantly changes the outcome for the plants I guess I need to group plants by ph and have separate ponds where I control the ph accordingly. By the way, plants also appear to care about electroconductivity levels of the water and that parameter also differs in their preferences. Should I take this into consideration as well?
    – kr3t3n
    Commented Mar 2, 2017 at 9:51
  • Whoa!! You are going to do well, Georgi! My goodness, yes, I would take that into consideration! I am dying to hear some answers from my colleagues that DO this stuff for real. I am learning vicariously I guess, grins! Gosh, please stay in touch...send a diagram of your system. I would think this would get you even better responses!! Thank you for using our site!!
    – stormy
    Commented Mar 2, 2017 at 17:57
  • Electroconductivity would be about electrolytes...? My hubby is an electrical engineer and I would love to give him something to chew upon. He is getting into gardening these past few years and doing really well. I know nothing about this...I am very interested as heck have never come across this and of course this would be important...huh!
    – stormy
    Commented Mar 2, 2017 at 18:02
  • I've found this link with the ph and EC levels of plants homehydrosystems.com/ph_tds_ppm/ph_vegetables_page.html Now I'm not sure whether I need to have separate fish ponds where I use the water (with different ph and EC levels) to "feed" the separate groups of plants.
    – kr3t3n
    Commented Mar 3, 2017 at 9:36

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