Maq's Substrate Experiment

[MichaelJ]

I'm honestly trying to follow standards of fair science.

Personally I would say you're doing pretty good in that respect! We don't have much people around in the hobby with the passion, skills, time and equipment etc. to do what you are doing.
... as long as we are all honest in our interpretation about how Mother Nature comes out we should all be able to learn something. I am a scientist of sorts in my day job and I can say that the level of rigor you are putting forward on a topic dealing with an astounding amount of known and unknown variables is praiseworthy. Biases? Of course! Is it perfect? Of course not! No non-trivial experiment are ever conducted without a certain level of uncertainty, bias or wrong-doing at initial conditions - it's impossible! However, with careful analysis we can still learn a lot from what comes out of this experiment whichever way it goes.

Cheers,
Michael

PS: Of course, if the experiment is not coming out the way some of us want it to, it's heresy and we will burn you at the virtual stake! - like the Spanish inquisition did to Giordano Bruno

 

[_Maq_]

Thank you.
Yes, it's the interpretation of data which requires sober approach. We should not expect getting a definitive proof of anything. Hopefully, we'll get interesting information to ponder.

 

[hasan66]

So, folks, tell me, vote: Tropica or ADA?

oase scaperline soil 😬

 

[dw1305]

Hi all,

How do you explain the comparable amounts of NH3 and NH4 at such a low pH?

That's misunderstanding. It's only one measurement expressed in three different ways. It cannot measure separately dissociated and undissociated ammonia/um.

You have to measure them as Total Ammoniacal Nitrogen (TAN), by either acidifying the solution to convert all the TAN to ammonium (NH4+) or adding a base to convert it all to ammonia NH3 <"Help understanding NT Labs liquid ammonia test"> .

cheers Darrel

 

[hax47]

Hi all,
You have to measure them as Total Ammoniacal Nitrogen (TAN), by either acidifying the solution to convert all the TAN to ammonium (NH4+) or adding a base to convert it all to ammonia NH3 <"Help understanding NT Labs liquid ammonia test"> .
cheers Darrel

Under pH 6, it is already acidified enough, 99.9% should be NH4+.

 

[_Maq_]

Under pH 6, it is already acidified enough, 99.9% should be NH4+.

Yes, but the producer of testing chemicals can't know. Therefore I have to drop TWO reagents - first is to move pH either very high or very low (I don't recall) while the next one adds the yellowish tint which is then measured by the photometer.

 

[dw1305]

Hi all,

Under pH 6, it is already acidified enough, 99.9% should be NH4+.

It would be, and you can use <"the chart of pH and temperature"> to get the ratio of NH4+ : NH3.

Yes, but the producer of testing chemicals can't know. Therefore I have to drop TWO reagents - first is to move pH either very high or very low (I don't recall) while the next one adds the yellowish tint which is then measured by the photometer.

I like TAN as measure, the issue for me is that "ionized" can become "unionized", <"with disastrous results">.

Cheers Darrel

 

[MichaelJ]

I like TAN as measure, the issue for me is that ionized can become unionized, with disastrous results.

Very much so.

Here is a calculator for that (free (toxic) Ammonia NH3 from TAN as a function of pH and water temperature) for anyone interested.

Free Ammonia Calculator (Javascript)

For the math inclined:

https://floridadep.gov/sites/default/files/5-Unionized-Ammonia-SOP_1.pdf

Cheers,
Michael

 

[dw1305]

Hi all,

first is to move pH either very high or very low (I don't recall) while the next one adds the yellowish tint which is then measured by the photometer.

Sounds like the <"Nessler" method">, where the reagent converts all of the TAN to NH3 gas.

......... a solution containing K2HgI4 and KOH (the base)

...... Nessler’s reagent (potassium tetraiodomercurate (II)) reacts rapidly with ammonia under alkaline conditions to form an orange-brown product. Turbidity due to hardness salts is prevented by adding the sample to a solution of Rochelle salt prior to adding the Nessler reagent.......

<"Ammonia Nessler Test Method, Technical Information - Palintest">

If your test uses K2HgI4? It should have warning pictograms on the label.

cheers Darrel

 

[_Maq_]

It should have warning pictograms on the label.

Oh yes, many many strong warnings everywhere. Even skin contact can be lethal.

 

[_Maq_]

Day 5 (Dec 12): fertilized iron cca 8.4 µg/L, in the form of FeCl3 (iron chloride).
Day 9 (Dec 16): water change 50 % (=10 liters), with mineralization.
Day 10 (Dec 17): measuring.


Plants are fine, growing visibly (but slowly by hi-tech standards). The only minor issue is with Myriophyllum tuberculatum - its stems are fragile and broke in A, while in B one stem failed to root and dropped some leaves; I left the remnant flow freely. In D, water is less than perfectly clear. No algae, yet.

 

[Andy Pierce]

@_Maq_ could you add the day 0 values into the table, just for ease of comparison with the subsequent values?

 

[_Maq_]

could you add the day 0 values

On day 0 I measured conductivity before mineralization, just to see how much substances leach from the substrate. Only on day 1 the water had been already mineralized.

 

[_Maq_]

Day 14 (Dec 21): Fertilizing micros: boron 1.6 µg/L, manganese 4.1 µg/L, zinc 1.6 µg/L, copper 0.48 µg/L.
Day 16 (Dec 23): Fertilizing iron 8.4 µg/L. Measuring:

 

[Happi]

You can see that the dosing is lean. I think it's the best way to see if root tabs or aquasoil contribute to improved growth.

My only main concern is that root tabs will end up leaching into the water Colum within the first week or so. not sure if you are already seeing the increase in TDS and other nutrients in the water? Aqua soil will be doing something similar especially in the early stage. you can expect the robust plant growth in the setup with higher NH4.

A - silica sand

am particularly Interested in this setup to see how things play out. Overall, looking forward to see the end results.

 

[_Maq_]

A disclosure. Just for a fun, or perhaps in hope that I would discover something big, I've kept for myself what the tank D - custom actually is. Now I think differently, so I'm going to tell you.

A few months ago, @Simon Cole drew my attention to fungi Trichoderma. This fungus is known for supporting plants' rooting and growth. I've made an inquiry what sources of this fungus are commercially available in my country and I opted for this product: AgroBio Opava INPORO Pro Mix M. It's a blend of beneficial bacteria & fungi as follows:

To my surprise, it's neither a powder, nor liquid. It looks like a soft peat, presumably colonized by named bacteria & fungi.
24 days before Day 0 I put a layer of this "peat" at the bottom of tank D, then covered it by the same clean silica sand as in tanks A and B, and poured water only as much as to make the substrate wet but not fully submerged. I hoped that this way the bacteria and fungi would proliferate and get ready for the plants.
That's the whole secret.

 

[erwin123]

Noted that you have put a special root formula into tank D. Look forward to the results!

When its time pull your the plant to replant, can you also photograph the root system of the plant in aquasoil vs sand to see if there is any difference?
After reading up on the root systems of terrestrial plants, I am intrigued as to the 'additional' functions of root systems, from providing a 'home' for certain forms of bacteria, to secreting chelates that can reduce Fe3+ to Fe2+. This makes me wonder that for plants with an emersed form, like the Rotala Indica Bonsai above, which are tiny plants but with long root systems, whether healthy root system=healthy plant?

 

[_Maq_]

When its time pull your the plant to replant, can you also photograph the root system of the plant in aquasoil vs sand to see if there is any difference?

A good idea. I will.

By the way, I've made an interesting experience with Rotala indica. It grows poorly in sand size 0.6-1.2 mm. For many months, the growth is abysmal. However, the plant grows vigorously in a sand size 1.4-2.0 mm. The grain size obviously makes some difference.

 

[_Maq_]

Day 19 (Dec 26): WC 50 % with front-load remineralization/fertilization. An hour later I've measured:


... and made some pics (not to get lost, please, see the name of each pic):


You can see, plants are generally doing well. Some melting occurred on Rotala macrandra TC in tank D (the three plantlets at the left side) but they seem to hold successfully the uppermost leaves and survive. I'm a bit disappointed because I expected the microbial inoculate protect the plants from such events.
Another point of interest are the signs of iron deficiency on Ammannia gracilis TC and Ludwigia inclinata Meta.

Ammannia: Iron deficiency is quite pronounced in tanks A and B, while the rest seems to be in better shape.

Ludwigias present a rather different picture:


Only in tank D, Lugwigias seem to be in full health, while (interestingly) in tank C, the iron deficit looks quite hard (but probably overcome, already).
I really would like to believe that the microbial inoculation in tank D helped the plants to cope with iron deficiency better than in other tanks. But of course, we cannot consider these observations as a proof, just a suggestion - "perhaps".
I've been intrigued by signs of iron deficiency in tank C. Aquasoil is supposed to be a rich source of all nutrients (and measuring ammonia/um seems to confirm that). How come iron deficiency, then? What if phosphates leached from aquasoil prevented some plants from acquiring iron? Remember, Ludwigia cuttings were rootless, depending on nutrients in the water column.

 

[_Maq_]

I've failed to mention that from the very beginning, water in tank D is not as crystal clear as in other tanks. Humic substances, perhaps. But then, it's interesting that this hue is completely absent in tank C.
Day 26 (Jan 2): Measurements:

Iron deficiency seems to persist, so today I've added 16.8 µg/L iron (as ferric chloride).
Interestingly (and rather surprisingly), no trace of algae, yet.