# Tannins.



## Jaseon (16 Dec 2021)

Do they promote fish health or not. If yes how?

A lot of people say Tannins have medical qualities.

A few things i feel are true, and some obvious ones is that it can lower the ph, although i suspect the volume of leaf or wood you're using would have to be substantial for that to happen.

Results of experiments showed that tannins possess antimutagenic potentials as well as antimicrobial...fair?


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## dw1305 (16 Dec 2021)

Hi all,


Jaceree said:


> Do they promote fish health or not. If yes how?


They do, black-water fish come from habitats like this:

From <"Collecting in the Río Tapiche drainage">, from Norwegian _Apistogramma_ breeder TomC's travelogue pages.






Have a look at <"All the leaves are brown"> as well.

In "_All the Leaves are Brown_" Colin Dunlop references <"Dr Christian Steinberg (2003). Ecology of Humic Substances in Freshwaters: Determinants from Geochemistry to Ecological Niches. *ISBN-10:* 3540439226 *ISBN-13:* 978-3540439226"> who has done a lot of work in this area.

<"Phenol-rich fulvic acid as a water additive enhances growth, reduces stress, and stimulates the immune system of fish in aquaculture">.

cheers Darrel


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## Jaseon (16 Dec 2021)

I couldn't believe how soft the water samples were taken from those streams.

I was actually contemplating buying some of those exotic leaves that some rave about, and thought hang on what the hell am i doing.


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## Nont (16 Dec 2021)

Jaceree said:


> I was actually contemplating buying some of those exotic leaves that some rave about, and thought hang on what the hell am i doing.


You can use almost any dried leaves from fruit trees, make sure you avoid the trees with white sap and boil before uses them. I have inches of leaves in my Rio Negro tank and let them dissolve on its own.


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## hwscot (16 Dec 2021)

Have been wondering about this. We've a few cherry trees in our garden, and this year I've collected some leaves for potential use in a tank. They've dried nicely (albeit to a very dark brown - shame to lose those golds and russets). Can someone explain if / why it's important to boil them before use? I wasn't intending to. There have been no herbicides or pesticides near them, and one of the advantages of being in a windy place is that the air is pretty clean of pollution from traffic. The leaf debris in blackwater streams is presumably not introducing pathogens.


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## Nont (16 Dec 2021)

hwscot said:


> Can someone explain if / why it's important to boil them before use?


To avoid introducing any bacterias into your tank.


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## dw1305 (16 Dec 2021)

Hi all,


hwscot said:


> Can someone explain if / why it's important to boil them before use? I wasn't intending to.


No, I just chuck them straight in. I have a bag of dried Oak and Beech leaves stored, but for <"_Magnolia grandiflora, Camellia x williamsii_  and _Eriobotrya japonica etc_"> I just pick them up from under the tree and add them in.

cheers Darrel


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## mort (16 Dec 2021)

I just chuck them in as well. Boiling them is just adding a safety factor that you don't need from a clean source.

This explains a few things and gives some ideas for free botanicals









						Using leaves in your tank
					

Collect fallen leaves from a nearby forest and use these to decorate your tank.




					www.practicalfishkeeping.co.uk


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## Jaseon (16 Dec 2021)

I am reading that leaves dont have the same amount of tannins, and or medicinal benefits although i dont seem able to find any data that supports it. Many of them claim the same thing so im guessing its just the leaves themselves that hold these attributes, or are some leaves higher in these values than others?


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## MichaelJ (16 Dec 2021)

mort said:


> I just chuck them in as well. Boiling them is just adding a safety factor that you don't need from a clean source.
> 
> This explains a few things and gives some ideas for free botanicals
> 
> ...


Thanks for posting @mort.





This one is interesting. I am mostly paying attention to the measurement for Catappa (Indian Almond) leaves, as this is what I am using. I did not realize that the pH lowering properties is as fast acting as this chart suggest (RO water), but also that it is somewhat shorter lived than I had expected.  I am not surprised however that it won't do much for lowering pH in hard (buffered) water, except for stabilizing the pH.

I am buying rather expensive dried Indian Almond leaves and I never boil them - seems counter productive to me to boil out the beneficial properties. I just dump them into the tank and let them float around - they will sink eventually and I can put them where I want them. 

Cheers,
Michael


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## mort (16 Dec 2021)

Jaceree said:


> I am reading that leaves dont have the same amount of tannins, and or medicinal benefits although i dont seem able to find any data that supports it. Many of them claim the same thing so im guessing its just the leaves themselves that hold these attributes, or are some leaves higher in these values than others?



Different species do have different properties. Oak is great for tannins and similar to catappa but you'd need more to get the same benefits. Some leaves do very little apart from look good and others you'd really want to avoid.


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## Jaseon (16 Dec 2021)

> mort said:
> 
> 
> > Different species do have different properties. Oak is great for tannins and similar to catappa but you'd need more to get the same benefits. Some leaves do very little apart from look good and others you'd really want to avoid.



Yeah i did read in one of the links posted that some leaves release more tannins than others. I suppose it depends on what you want. Im not a big fan of the darker blackwater biotopes, but only because you tend not to see bugger all lol. I have a tank with a large piece of bogwood set up for my farther in law. You can see the amount of tannins that come out of there through the water changes. It does colour the water, but not overly so, and no doubt the fish enjoy the benefits.


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## Kelvin12 (17 Dec 2021)

Hello Everyone,  in the posted charts with the use of Catappa leaves with RO water and the dramatic PH drop after an extended time would you think this was with using re-mineralized water.  The eventual PH drop is way low on the scale.
Quite a few leaves mentioned here to try thanks to all for the input.  
Dirk


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## MichaelJ (17 Dec 2021)

Kelvin12 said:


> The eventual PH drop is way low on the scale.


Hi @Kelvin12 , Yes, I was surprised how fast it drops as well - Of course, we do not know the exact details of how this test was conducted such as leaf mass vs. water amount etc. or the exact properties of the RO water or tap water, but at least you can likely assess the impact on pH of the various leaves relative to each other.
Cheers,
Michael


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## Kelvin12 (17 Dec 2021)

G'day @ MichaelJ it worried me as well and I thought maybe it was a missprint..  Does seem odd one water could effect the results so differently.  
Dirk


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## brhau (17 Dec 2021)

I did a smaller version of this experiment, and did detail what I could of the methods: Leaves for Apistos


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## MichaelJ (17 Dec 2021)

Kelvin12 said:


> Does seem odd one water could effect the results so differently.


Hi @Kelvin12  It might seem so, but it's not. The higher the KH (i.e. more Calcium carbonate / CaCO3) the more resistance there will be to a change in pH as the CaCO3 will react with (absorb) the acid (H+ compounds) _released_ from the leaves. The hard tap-water used in the experiment would presumably be somewhere in the 12-15 KH/GH range (depending on the definition of _hard water_) which would have a relatively high order of resistance to pH change and why you only see a modest and relatively short lived drop in the tap water.

Cheers,
Michael


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## brhau (17 Dec 2021)

When I did it, I tried the experiment with RO water and found that the acidification happened too quickly—all treatments had gone to <= pH 6.0 at the first time point. So I had to adjust the paramerers such that I could see clear separation between the treatments over the timescale I was measuring. The water matters a lot, both empirically and from a first-principles standpoint.


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## dw1305 (17 Dec 2021)

Hi all,


brhau said:


> When I did it, I tried the experiment with RO water and found that the acidification happened too quickly—all treatments had gone to <= pH 6.0 at the first time point.


The issue is really the pH scale, it just doesn't "work" as you approach pure H2O.

It is because pH is both a log10 scale and a ratio. It is the ratio bit that matters, pH 7 just indicates that there is a balance between protons ~ hydrogen ion (H+) donors ("acids") and hydrogen ion acceptors ("bases").

Pure water is "self-ionized", but any addition of acids will cause the pH to drop rapidly, which we can see when <"the 0.15%"> of the <"0.6 ppm of CO2"> that <"goes into solution as carbonic acid"> (H2CO3 ~ as HCO3- and H+ ions) and drops <"the pH of pure rain water"> to pH 5.6 ish.

This is why drop-checkers etc use some carbonate buffering (the 4 dKH solution) and a narrow range pH indicator. This allows us to get some measure of the "amount" of acid added, because without any buffering the pH scale is, pretty much, meaningless.

cheers Darrel


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## brhau (17 Dec 2021)

I think I have may have mixed tap and RO 50/50 on my first try for this reason, I can’t remember now. At any rate, there definitely wasn’t enough buffer to see any separation, since my water is soft to begin with. It was a still useful to know which direction to adjust.


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## Kelvin12 (18 Dec 2021)

Well decided to add some of the dead leaves recommended by Darrel and they immediately flocked to them.   It also looks a pretty interesting natural addition.  Think I'll  be doing this a lot more now.  
Dirk


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