Substrate Nutrient

[Rodgie]

Good Morning/Evening,

Hi everyone, It's been a while since my last post. Tomorrow I'll start dosing EI method 2x a week in my 15 gal tank with plants like anubias, java fern, water spangles and amazon sword. My question is, will the substrate (Flourite Black Sand) be able to absorb nutrients from the water? I'm tight with budget and i only have the seachem root tabs (which is already in place) for my amazon sword. The plant is growing new leaves a lot. But, the old ones (the original leaves when i bought it) are already starting to have deficiency signs.

Thank you,
Rodgie

 

[Konsa]

Hi
When U bought the plants they were grown emersed most probably.Those leaves will not adjust to life underwater and are doomed.
Just trim them off if U have new growth as they will only release organics in water.
Regards Konsa

 

[Edvet]

Dosing in the water should be sufficient, the plants will absorb the nutrients with the healthy leaves.

 

[Rodgie]

Thank you Konsa and Edvet, So just to double check my question. Amazon sword (root feeder) will still benefit from the ferts present in the water column? How?

 

[Konsa]

Hi
Yes that is correct.Aquatic plants are able to absorb nutrients via their leaves.This includes the so called heavy root feeders.Water column fertiliser is always beneficial but not always needed if the substrate is rich enough depending on the type of setup.
I have two low tech tanks atm with plain sand and water column fertiliser only and the plants are doing good. Including several Cryptocoryne varieties.
Regards Konsa

 

[Rodgie]

That's good to know sir! It'll save me some money. I thought I'll have to buy special root tabs for Macro.

Always good to have this forum available. The best out there! Thank you!

 

[Konsa]

Hi
U definitely don't need special root tabs.
Having any root tabs is just a way to get some nutrients in when not dosing the water column regularly.
Don't get me wrong tho if U fancy putting some it will benefit the plants too.Both fertiliser metods are not mutually excluding eachother.Many do combine them both with good results.

Regards Konsa

 

[dw1305]

Hi all,

Yes that is correct. Aquatic plants are able to absorb nutrients via their leaves.

@Konsa is right, even terrestrial plants can take in nutrients through their foliage, when those nutrients are in solution.

From <"https://www.rhs.org.uk/advice/profile?PID=304">

Foliar feeding: This is the application of a dilute solution of fertiliser to the leaves of plants, useful as an emergency treatment for correcting nutrient deficiencies or for providing quick supplementary feeding. The absorption of liquid fertiliser is greatest where leaf surfaces are tender, particularly on the under surfaces of leaves or on young leaves that are just expanding.

The other thing to note is that all plants (including cacti etc) can only <"take up nutrients as ions">, charged particles that are in solution in the soil water. So even root feeders are really getting their nutrients from the water column (in this case the water column that is in the substrate). This is also why you can grow plants successfully hydroponically in <"NFT">, <"aeroponics"> etc.

There are still reasons for both having a substrate, and adding nutrients to it. If you have a substrate with humus, or clay minerals, it has some <"ion exchange capacity"> (AEC/CEC) and will retain nutrients which can become available to plant roots.

Also, in the substrate, there will be zones of fluctuating REDOX values where formerly insoluble oxidised compounds <"may be reduced and become plant available (as ions)">. This can be particularly important for micro-nutrient availability.

cheers Darrel

 

[HiNtZ]

I've had great success with just inert sand substrate and full EI dosing.

You have to be on point DAILY with the ferts when rubbing high light with the gas, so would recommend a decent auto doser. If I missed just one day it would spell disaster for at least two weeks in my tank.

Now I run the same light and gas with westlands pond compost capped with sand and only dose iron, potassium, a tad magnesium and N/P as needed.

This works much better for me as I am away for a week at a time and it takes a long time for any problems (algae etc) to manifest themselves.