Do plants soften water?

[tiger15]

Since plants take up calcium and magnesium, do plants soften water? So if I grow plants in inert substrate, the gH will go down without water change or gH dosing.​

 

[rebel]

Yes, it would. Whether it's measurable would be dependent on your testing accuracy and plant mass.

If you don't trim/or water change, I think the leaf degradation would return the minerals back to the water however.

 

[HiNtZ]

Since they absorb these nutrients from the water while alive and growing, do they then return the same amount back when they die off?

 

[rebel]

Since they absorb these nutrients from the water while alive and growing, do they then return the same amount back when they die off?

Yes. They would. My assumption is that the waste can be completely recycled by the bacteria/fungi/archae in the tank. I don't know how long the complete cycle may take.

 

[tiger15]

Yes, it would. Whether it's measurable would be dependent on your testing accuracy and plant mass.

If you don't trim/or water change, I think the leaf degradation would return the minerals back to the water however.

If I provide direct sunlight to promote vigorous plant growth, dose macros and micros periodically, do regular trimming and removal of floaters, don't do WC but top off with tap water, don't feed inhabitants that live off algae, bio film and natural critters, do you think the water will soften over time?

I have an outdoor summer tub and a window sill planted bowl that fit the scenario. I am asking because I want to know if my moderately hard tap water will be softened by plants so I can keep soft water fish and shrimp.

 

[Edvet]

google: biogenic decalcification😉

 

[rebel]

I want to know if my moderately hard tap water will be softened by plants

I doubt it. Unless you top up only with RO or rain water.

 

[tiger15]

google: biogenic decalcification😉

Good read, but only relevant to certain type of plants that can extract CO2 from carbonate. I haven't observed any white deposit, so either I don't have the type of plants or the right conditions for biogenic decalcification to occur.

But plants do feed on Ca and Mg, which are essential nutrients for plant growth. But will incorporation of Ca and Mg in plant growth reduce hardness? Interestingly, dead plants (peat moss) will do it and is commonly employed to soften hard water through different mechanism.