# Submersed culture of blackwater crypts



## Kai Witte

I've been keeping blackwater crypts submersed for decades, often in small breeding tanks and other low-tech set-ups. I never had any problem when their natural environment got reproduced reasonably well:
*Rule #1.* No carbonates in the water nor in the substrate/mix.
*Advice #1.* A low pH is your friend.
*Suggestion #1.* Keep nutrients limiting. 
*Common sense.* Don't overdo lighting.

I'm sure there are dozens of possible ways to do it - I'm relaying just my experiences as some food for thought here...

In my early days, I've usually been using peat to lower the pH (pH 3.5-4.5 is a good target range) of pure rain water (or DI water) and also to add some organic stuff (fulvic acids, etc.). Substrate ranged from pure quartz sand or weathered granite sand to pure peat. Additional nutrients came mostly from fish feeding.

Later on, I experimented a lot to avoid unsustainable use of peat. Adding autumn leaves (beech, oak, maple, etc.) workes quite nicely but you have to account for introducing (also) more readily digestible organic material (most blackwater fishes don't mind unless oxygen levels go down to zero...  ).

Nowadays, I usually just use leaf-mold and throw that in a tank filled with DI water. Just kidding? No! This is not for the faint of heart though... 

Depending on the quality of your leaf-mold, you have to expect getting some algae but usually the "nasty" ones will get away eventually. You may not want to try this first with a large show tank though. 

If you're a bit hesitant, just make an almost fluid leaf-mold slurry and fill the tank 0.5-1 inch (you can use more but it's usually wiser to start with a little and add more later on). Drop in some crypts and let them grow emersed & propagate for a while; also see my thread on emersed culture: http://www.aquaticplantcentral.com/forumapc/crypt-nuts/13862-peat-swamp-habitat-for-crypts-in.html. (Consider adding some more slurry and waiting some more weeks.) Then *gently* fill the tank completely and, presto, you have a real blackwater habitat!

Good luck!


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## Kai Witte

> I was thinking of doing something like a layer of the leaf litter under some coarse sand.


Any top layer compacts the leaf-mold. It can work but usually it's not a good idea. Unless you're reproducing a blackwater stream with fast current, you don't need a top layer - just some imagination and possibly several weeks of emersed culture as a head start...


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## Kai Witte

An example from a tank with lowered water level to allow enough space for flowering...


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## Kai Witte




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## AaronT

Thanks Kai, that was very informative. I'm guessing then that the blackwater species don't need significant flow in your experience? Do you inject CO2 at all or let nature take its course?


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## ts168

Kai Witte said:


> An example from a tank with lowered water level to allow enough space for flowering...


Hi Kai, I have some question to ask about this setup.

1. Is there any pump/filter in the setup to have water movement?
2. Is there any fish inside? I believe the fishes will love the cosy environment. Especially the boraras fishes.

Nice setup.


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## Kai Witte

I often have a little current in my blackwater tanks but that is generally for the fishes and other inhabitants; the crypts certainly benefit a bit from a little water movement but don't need it. This tank has been "sitting" without pump nor heater for over a year... 

Blackwater fish really feel at home in such a tank and I've been breeding species from genera like Betta, Parosphromenus, Boraras, Rasbora, etc. in such set-ups. No fish in this one yet since I'm waiting for Paedocypris. A low density of fish, shrimp, etc. helps to provide some nutrients; don't try snails though!


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## HeyPK

> ....Later on, I experimented a lot to avoid unsustainable use of peat.......
> 
> ......If you're a bit hesitant, just make an almost fluid leaf-mold slurry and fill the tank 0.5-1 inch (you can use more but it's usually wiser to start with a little and add more later on)..........


Kai,

Why is the use of peat unsustainable? Does the peat decay and disappear?

Why is it wiser to start with a little leaf mould and add more later? Do you have too much decay if you add it all at once? Do the plants do bettter if you add it in stages?


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## Kai Witte

Hello Paul,



> Why is the use of peat unsustainable?


No problems with the intelligent use in aquaria but it's the mining of bogs for peat which is unsustainable. 



> Why is it wiser to start with a little leaf mould and add more later? Do you have too much decay if you add it all at once? Do the plants do bettter if you add it in stages?


That's an old horticulturist's rule: Plant seedlings, cuttings, etc. in small pots. Once their roots have grown throughout the substrate, move up to larger pots. (There are notable exceptions to this rule though!)

Same-o with crypts, especially if you start with small runners or plants stressed from shipping. If I have large, healthy runners of decent size, I often use regular pots right away. But if either the plants or the leaf-mold are not optimal, starting out with less substrate seems to be the safer, more foregiving approach.

BTW, I do add leaf-mold from time to time to feed vigorous plants.


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## ruki

So carbonates cause problems?


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## Kai Witte

Yup, carbonates are pretty much antithetical to blackwater crypt habitats - kinda like keeping polar bears in a thermal spring... 
There are many plants from acidic habitats who have evolved past being just tolerant to acidic conditions and will not grow well in any alkaline environment. Most of these plants don't need it as acidic as in nature to thrive. OTOH, carbonates are not important - so, it's easier to keep them out of the equation rather than adding unneccessary complexity.


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## kirana1

Dear Kai witte

could you give me the crypt species that you categaries as a black water crypt ???

sorry to asking you this stupid question.

and is there any crypt that can't cultivate emmerse such as c. aponogetifolia, albida , usteriana or striolata

because i am trying to cultivate those crypt emmerse but hey are melting

nico


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## rs79

I have poor luck with albida submersed and can do nothing wrong when I grow it emersed. It even survived a light frost here that killed african violets.

I'm not sure APO does well emersed. It's got long leaves and lives in fast flowing streams. It's vary hardy and prolific submersed.

UST I don't have enough experince with - I had it only briefly once and was away on business a lot and killed it. I do not believe it will get nearly as big emersed though. And it's a BIG plant.


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## HeyPK

I had good luck with albida once submersed, but poor luck on a recent, second try. The first time was long ago, and I grew a big mass of it and took all of it to the LFS and essentially gave it away. I didn't know it was hard to grow back then. All I remember then was that I grew it in soil that had a lot of partially decomposed leaves in it and that I was rather parsimonius with nutrients. It is the plant in the background.


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## Kai Witte

Hello Nico,



> could you give me the crypt species that you categaries as a black water crypt ???


I'll try to post a list later.



> and is there any crypt that can't cultivate emmerse such as c. aponogetifolia, albida , usteriana or striolata


As already noted, it doesn't make much sense to culture aponogetifolia emersed - it's only vigorous submersed and will flower if it gets enough light.

I haven't encountered problems growing albida emersed.

Also usteriana should do reasonably well emersed. However, there are quite a few distinct strains and it may be possible that your's prefers submersed culture - any pics?

I had striolata growing emersed fairly well a long time ago. It is usually not easy to grow either way (although there are also very different strains) so I suspect that your problems with this species are more general than linked to emersed culture.


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## mats808

Kai,
For emersed growth:
If using 100% RO/DI water, should you add back any tap water at all or just go with the 100% RO/DI? For blackwater Crypts do you see any problems with a potting mix consisting of ADA amazonia, chopped up sphagnum, and some potting soil? What about 100% amazonia?
thanks,
aaron


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## AaronT

You want to use 100% RO, rainwater or DI water. Think zero hardness and a pH of 5.0 or even lower. I would leave the potting soil out of the mix as it will add unwanted hardness. 100% amazonia should work well enough. Honestly, I think that's the best way to go as soil and leaf litter have always introduced bugs and other pests into my setups.


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## Kai Witte

Hello Aaron,

Welcome back to crypts! 

Yes, I do mean 100% pure water: no tap water addition, no cheap/old RO unit with bad membrane, whatever. BTW, blackwater fish love it, too!  Remember that typical blackwater habitats (in SE Asian lowlands) receive all their nutrients from the rainwater: Thus, the run-off from undisturbed peat swamp forests and heath forests has even less nutrients than rainwater!

I also would advise against potting soil: chances are that it has way too much nutrients added (a sure way to kill a crypt, especially when stressed from shipping) and will start rotting away if not fully rooted within "seconds"...

I've heard that some folks utilizing ADA soil mix Amazonia and Malaya but it would convince me more if somebody would test both brands as well as the mix and show us pics how the crypts fare. Mixing any additional organic matter with any mainly mineral soil may result in fast(er) decomposition - it won't hurt to incubate any moist (not wet!) mix for at least a month before putting any plant in, especially when planning to inundate the soil for semi-emersed or submersed culture.

I'd be more inclined to use Sphagnum as a "top dressing" rather than mixing it into a soil, especially when waterlogged. Actually, I often have some live Sphagnum growing in my blackwater crypt pots.

I haven't got any plant pests from acid leaf litter so far but there is a high chance to obtain small planaria species with collected soil. I've not tested yet wether these pose any problems for breeding fish or shrimps. Apparently not in my set-ups but I'm not feeding heavily either.


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## mats808

Thanks Aaron and Kai,

Kai,
Do you always use leaf litter to grow emersed blackwater Crypts? It doesn't sound like you like amazonia too much. Is there anything else that works well?

aaron


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## rs79

I don't know about Kai but the problem I have with "Amazonia" and "Malaya" soils is that they're proprietary.

If I say "beech leaf litter unser sand" anybody in the world can read it and reproduce, or get close eough to work. Saying "Use Amazonia" means "buying amazonia" and why would we want to do that when we typically make our own substrates.

Unless we live at one of the two poles there are plants that grow on the waters edge near where you live. Go look at that and then reproduce it in a way that makes sense to you.

Around here that means "well composted manure under sand" and I'm convinced *any* Crypt will do well with that.

Looking at Kai's picture above reminds me of the way Charlie Drew's "giant red Crypt" grows for him (in the above mentioned substrate) in tanks less than two feet tall.


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## jazzlvr123

very interesting read its amazing how much you learn just browsing around this site lol thanks for posting kai


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## PetiteFleurBleue

Hello, after looking for plants that would do in my "hot" blackwater tank with a pH around 4, durng a while, it seemed to me that unless I could find the _Cabomba aquatica var schwartzii _ the best choice would be the unfindable _pallidinerva _ cryptocoryne, or the schlulzei. So really glad to find this forum and this thread (with some other threads) to list the blackwater sp. of _Cryptocoryne_.
here is the list I found here:
http://www.aquaticplantcentral.com/.../33818-questions-about-blackwater-crypts.html

By the name of the jpg. file, the one photographed on the first page of the present thread, would be _longicauda _

If I welle understood, after looking for information about the current crypts in the hobby, all the crypts sold in my local petshop are hard water species. I'm trying a common _wendtii_ crypt (I imagine, I don't have a clue about the determination but it's growing in our local aquarist club) in the tank, it doesn't die but it seems to me that it grows only when the pH rise upon 5, when the pH goes down it freezes.
I used this site to get the descriptions of my local store sp.:
http://www.nationaalherbarium.nl/cryptocoryne/Gallery/min/min.html

Which would be the more suited cryptos for a acid pH around 4 AND a high temperature around 29°C, and the lowest TDS I can obtain for my _Dicrossus filamentosus_.

Which _Cryptocoryne_ species are the most suited for submersed culture?
It seems that the _longicauda_ would, but can it handle high temperature?
http://aquaworld.netfirms.com/Labyr...start=20&sid=8b17b6ffb5101bf8e34cae361b0517d6

And last but not least...

Because to start the submersed culture of blackwater crypts it way be another difficulty...

How may I have a chance to find these Cryptocorynes???

hope it can be easier than getting _Paedocypris_ !?!


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## Kai Witte

Hello PetiteFleurBleue,

Welcome to the forum!
Is there any specific plant (like _Myosotis_?) connected with your nick name in French? 



> after looking for plants that would do in my "hot" blackwater tank with a pH around 4, durng a while, it seemed to me that unless I could find the _Cabomba aquatica var schwartzii _


You'll need loads of light to get C. aquatica growing well at high temperatures! And still some other leaves for spawning Dicrossus... 



> the best choice would be the unfindable _pallidinerva _ cryptocoryne, or the schlulzei.


I wouldn't recommend schulzei (more of a rainwater stream species). While pallidinervia would be suitable, I'd recommend other blackwater species to start with. Most (all?) blackwater crypts don't have problems with higher water temps.



> By the name of the jpg. file, the one photographed on the first page of the present thread, would be _longicauda _


Yes, the inflorescence is from a longicauda - sorry for not mentioning this in that thread!



> If I welle understood, after looking for information about the current crypts in the hobby, all the crypts sold in my local petshop are hard water species.


Yes, all commonly sold crypts are "tapwater hardy" - you need to obtain more specialized crypts from other sources.



> How may I have a chance to find these Cryptocorynes???


Send me an email... 

(BTW, to the others in the audience: I'm behind with my emails - if you're waiting for an answer from me just give me a kick in the ...)


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## PetiteFleurBleue

Thanks a lot for your answers.

Well "Petite Fleur Bleue" would be almost linked to _Myosotis_.

On french forums, full of polemics, started generally for the pure pleasure of polemics, your nickname must inspire peacefullness and kindness to avoid being banned.

With a nickname like Darth vader, you can't repply the half you can do with a name like "pretty little duckling", that would inspire more compassion, no admnistrator can be mercyless enough to crush a Myosotis or a little duckling. _Myosotis_ is a pretty good nickname, maybe "Joli bouquet de _Myosotis _" is even better than Petite Fleur Bleue!

Indeed, _Cabomba aquatica_ wouldn' match my main interest, the "periodicaly flooded broad leaved riparian vegetation".

I rode that _Spathiphyllum wallisii _ had been used to spawn _Pterophyllum altum_ as an imitation of a natural rainforest _Spathiphyllum_, but it wouldn't fit in my tank and I'm not sure it would stand long the pH and température. As for an _Anubia_, the problem would be to find them a place to rest between these traumatic flooding events.

Blackwater cryptocorynes, that would enjoy these conditions permanently, would indeed be a really elegant solution I imagine.


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## PetiteFleurBleue

From this webpage about Sarawak:
http://natureye.com/uncategorized/expedition-journey-to-sarawak-part-2.html
I understood that at least these must be considered as blackwater species, but there are no temperature indication.

C. Pallidinervia 
C. Yujii
C. Zonata
C. longicaudata

If I well understood the thread, nutrients like ammonia may be a threat that would cause the vitrification of the cryptocorynes.
It also seems that some silt is present in some blackwater habitats, and I rode that silt can be usefull for Cryptoryne culture. But it was about the current species.

In all case, it seems that the species coming from really oligotrophic waters may be affected by the ammonia from the fish. In my tank I use really fast growing_Salvinia auricalita_ and _Ceratopteris spp._ to pump the nutrients.

Would this competition for nutrients and light be even beneficial for a long term growth of the blackwater cryptocorynes?

Since there may be in all case a presence of ammonium, is it possible to make a "classification" of the blackwater cryptocorynes upon the gradient of nutrient, or the gradient of pH from their typic location?


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## Kai Witte

There just aren't enough crypt records with detailed and reliable water parameter measurements available to make any definitive statements. A good guess might be that those crypts most often seen at the lowest pH will also be those with the fewest nutrients available. However, the differences will be very small and all actual amounts much lower than what the crypts get offered in culture! Actually, crypts grow exceptionally well at nutrient levels they can only dream of in nature; ammonia is also no problem at a low pH.



> Would this competition for nutrients and light be even beneficial for a long term growth of the blackwater cryptocorynes?


That will very much depend on the actual conditions in each tank: E. g. I'm trying to avoid excessive shading by fast growing plants since my light levels are low to begin with. High temperatures result in faster depletion of energy reserves - especially for submersed culture, I'd start without shading first (i. e. remove competing plants once crypts start to grow well).


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## cryptoria

Very informative and useful thread. Thanks for sharing!


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## Kai Witte

I haven't updated this thread for a long time.

If you're not yet taken by the dark side , have a look at Hein's detailed report with many nice pics: https://crypts.home.xs4all.nl/Cryptocoryne/Botanical/Documents/Berge/Berge2014.pdf
He describes his experiences with a huge blackwater tank he build for his living room! [Originally published in the German journal Aqua Planta - scroll to the end for the English version if your German is not up to it&#8230; ]

Most of the problems Hein reported could be avoided by the "dry"-start method suggested at the start of this thread.

He also mentions the tank apparently running out of nutrients resulting in thin leaves with translucent patches - maybe bor deficiency? The standard approach would be to periodically add more leaf mould: Kinda messy for a show tank though - however, most bits & pieces will quickly settle into the plant stands (if you pre-soak the soil and reduce the current for a few days); one might try to squeeze a fist full of soil and push it under the roots. You can also try to continuously add leaves and let them decay in the tank; however, autumn leaves won't yield enough nutrients to sustain heavy growth. You can try green tree leaves though - your shrimp will get enthusiastic once these get colonized by fungi, bacteria, etc. To support any bold plant growth though (and subsequent removal of biomass from the ecosystem), I guess adding small amounts of fertilizer (in addition to leaves) may be in order. I also hardly do any water changes if a blackwater tank is planted well and only very moderately stocked (with fish, shrimp, etc.).

Try to find fertilizer without any chelators though: EDTA/etc. are very slow to degrade and efficiently catch calcium (a trace element in our blackwater tank!). Plants can deal with chelated ions and take them up; however, fishes seem to get problems resulting in bony tissues not getting calcified enough (crippled growth, twisted backbone). Hein mentions similar problems with his _Pangio kuhlii_ loaches: This species does not seem to inhabit strongly acidic blackwaters (it's commonly found in rainwater streams and weak blackwater with a pH over 5). Some fish species are not be able to cope with typical blackwater (pH usually 3.5-4.5) and artificial chelating agents included with many fertlizers will increase the risk.

A secondary problem of just about any "lazy" gardening approaches is to avoid one plant species taking over the whole tank. However, this is just a cosmetic problem: If you need to make the tank into a scape, try to restrict yourself to a low number of plant species, preferably with quite different looks and very carefully plan the layout so that the stands are less likely to mix. Underground runners need to be completely blocked and keeping some distance between the stands is a good idea since you'll have tree leaves, "aerial" roots, wood, etc. near the soil which may hide runners escaping above the surface (and a crypt runner can easily grow half an inch per day). In many cases you'll notice a renegade runner only when it sends out a larger leave or two after settling into another stand - this is much easier to verify though if you can locate the offending runner in a no-plants area prior to surgically removing the plantlet including the whole runner&#8230; 

In a large tank, smaller crypts like _C. minima_ can be used as a under-storey, too. No carpet plants though; dwarf _Aridarum_ may work (haven't tried any from heathforest streams yet).

Have fun and report back with your own experiences, please!


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