# Nutrition uptake and pH:  garden soil, hydro and aquarium environment



## Cor (6 Aug 2019)

I often see images (charts) in which an ideal pH is shown that plant needs for optimum nutrient absorption.

But if I look further, they are almost always charts meant for soil (like gardenplants) Sometimes you see charts for hydroponics setups but never a chart for submersed plants.

But isn't there a difference between submersed and emersed plants?
ADA states that the pH should never be lower as 6.4, otherwise it is too acidic for the health of the plant.

For example:
for an gardenplant the 'best' pH for nitrogen uptake is arround pH 6.5
for an hydroponic plant it's about pH 5.8.

Is there any info about nutrition uptake related to pH for aquatic plants in their submersed environment?

Food for thoughts


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## dw1305 (6 Aug 2019)

Hi all, 





Cor said:


> But isn't there a difference between submersed and emersed plants?


Not really, all plants, even xerophytes from deserts, can only take up nutrients from solution as ions. 





Cor said:


> ADA states that the pH should never be lower as 6.4, otherwise it is too acidic for the health of the plant.


There are pH differences. Most soil has a pH of less than pH 7, even soil with some carbonate buffering. Water with any carbonate buffering tends to have a pH around pH 8. 

My guess would be that nearly all plants will grow at that sort of pH value. But it really depends on the plant, a lot of plants will grow happily at low pH. Against that plants like _Vallisneria _really don't like soft water. 

It would be really surprising if all aquatic plants had the same optimal pH value, mainly because the water in Lake Tanganyika is totally different in composition from the Rio Negro etc. In that particular case you could find _Pistia stratiotes_ in both water bodies, so that tells you that some plants aren't too bothered about pH. 





Cor said:


> Is there any info about nutrition uptake related to pH for aquatic plants in their submersed environment?


There is plenty in the scientific literature,  from <"plant physiology">, <"ecological studies"> and <"phytoremediation">.

cheers Darrel


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## Cor (6 Aug 2019)

As the pic also confirms: plants don't have all the same optimal pH value,but they do have a average.
You see that the 'best' nutrient availability and pH is in the range 6.5 in (potting) soil, and in Hydro at 5.8 But hydro is not the same as aquatic because with hydro the roots are in water and the foliage is not.
So I wondered what the best average availability in pH was with totally submerged plants.







dw1305 said:


> There is plenty in the scientific literature, from <"plant physiology">, <"ecological studies"> and <"phytoremediation">


Txs for  the internal link. Will study them


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## Edvet (7 Aug 2019)

I wouldn't get caught up in "ideal"parameters, tinkering with values to much can lead to other headaches. As we see in this forum there are a lot of beautifull tanks possible in all kinds of waterparameters, it's finding the balance between light and waterparameters that works best for your situation that gives the results.


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## dw1305 (7 Aug 2019)

Hi all, 





Cor said:


> So I wondered what the best average availability in pH was with totally submerged plants.


Somewhere in between pH 6 and pH 7 would give you maximal nutrient availability.  The chart above implies (with "lock-out") that those nutrients are totally unavailable outside of the marked areas, but that isn't really true, nutrient availability tapers off at sub-optimal pH values. 






Edvet said:


> I wouldn't get caught up in "ideal" parameters


That is very much where I'm coming from.

I use the same approach to both terrestrial (<"in the garden">) and aquatic plants (<"in the tank">). Find plants that are <"happy in your conditions"> and grow them.

If you look at @Akwascape's <"_Cryptocoryne parva_ carpet"> or @Tim Harrison's <"Windswept Eternity"> , these are using very hard water and are low tech non-CO2 tanks.

cheers Darrel


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## zozo (7 Aug 2019)

In terrestrial gardening we are dealing with Acid loving plant species and or Lime (base) loving plant species. According to this you can or need to adjust the soil contents or fertiliization scheme for optimal growth development. A good average with mixing these species up on the same soil or scheme simply would be Nutral than.. 

I guess the same goes for a range of (tropical) aqautic plants and in which paramters they naturaly evolved. For example we have a range of plants originating from very lime rich areas from southern India and Sri lanka. As far as i know the Microsorum philippine, some Aponogeton and Crypt spp. originate from that region and are Hard water lime loving aqautic plants that even are found in braksih waters in this region. And it seems to be prett tough to grow them in soft water. At least thats what i have and experienced with the M. philippne and an Aponogeton originating from there.

Than you rather go with what you get from the tap and steer away from plant species known to love it differently. Changing water column parameters according ideal hardness and pH is a pain in the neck, it needs constant attention and readjustment with every water change and is very labor intensive and little mistakes along the way can have drastic negative results if you playing with lifestock.


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