# Low-energy non CO2 tanks



## _Maq_ (11 Aug 2022)

Why do you folks always inject CO2 even when it's absolutely unnecessary, only leading to a too rapid growth, and even when the tank is obviously fish-oriented like this one?


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## plantnoobdude (11 Aug 2022)

_Maq_ said:


> Why do you folks always inject CO2 even when it's absolutely unnecessary, only leading to a too rapid growth, and even when the tank is obviously fish-oriented like this one?


While I would’ve been nicer in the delivery of the message, I do agree. A lot of the time co2 can cause more trouble than it is worth. Especially if you plan on growing easy plants such as crypts and stems.
For the vast majority of plants, co2 is completely unnecessary.

By the way @goldscapes the grassy green plant with thin leaves is not aquatic, it looks to be an ophiogon sp. It should do well with roots submerged but it will not do well fully submerged long term


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## erwin123 (11 Aug 2022)

_Maq_ said:


> Why do you folks always inject CO2 even when it's absolutely unnecessary, only leading to a too rapid growth, and even when the tank is obviously fish-oriented like this one?


@_Maq_ - in order to show why CO2 is 'absolutely unnecessary', please start a journal to show your tanks without CO2 injection, so that others can see what can be achieved.

Besides my CO2 injected tank, I also have a low tech tank thats a bit neglected, but if I can be inspired by nice tanks without CO2, I might pay more attention to it!


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## goldscapes (11 Aug 2022)

plantnoobdude said:


> By the way @goldscapes the grassy green plant with thin leaves is not aquatic, it looks to be an ophiogon sp. It should do well with roots submerged but it will not do well fully submerged long term


Good to know, thanks 🙏

Update: it was sold as Ophiopogon Kyoto, I’ll be replacing it, any suggestions?


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## goldscapes (11 Aug 2022)

_Maq_ said:


> Why do you folks always inject CO2 even when it's absolutely unnecessary, only leading to a too rapid growth, and even when the tank is obviously fish-oriented like this one?



In my case it was simple, I started out with plants that needed it. I kept it running out of habit to start with. However, when I have occasionally let the tank run empty, the plants have suffered and died back, so I keep it running because it works for me, leads to more pleasing plant density and healthier looking plants. 

Granted, I do need to be more careful introducing new fish and it’s a bit of a drive to get top-ups but I enjoy it and it’s a good learning experience.

I have a second tank, mainly anubias and elodea/hornwort, which doesn’t benefit from CO2 so I don’t use it.


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## _Maq_ (11 Aug 2022)

goldscapes said:


> it was sold as Ophiopogon Kyoto, I’ll be replacing it, any suggestions?


Eriocaulon sp. 'Vietnam'.


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## erwin123 (11 Aug 2022)

_Maq_ said:


> Eriocaulon sp. 'Vietnam'.



One of my absolute favourites, together with 'Japan'. 👍









						Eriocaulon 'Vietnam' - good alternative to Helanthium Bolivianum 'Quadricostatus'
					

This is a short note comparing my experience with Helanthium bolivianum 'Quadricostatus' and Eriocaulon 'Vietnam'. They look pretty similar and seem to grow to about the same size.   Alas, I have removed the Erio to make way for Rotala Macandra Narrow Leaf, as I embark on my own (less extreme)...



					www.ukaps.org
				











						Eriocaulon 'Japan' / 'Polaris' - alternative to Vallisneria 'Nana'
					

This is a mini-review of Eriocaulon 'Japan' (or 'Polaris'). As they had grown way too large, I pulled all of them out, and split one plant and replanted it after giving it a heavy trim. This gave me enough left over space to replant the Eriocaulon Vietnam (which I had pulled out) which has a...



					www.ukaps.org


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## goldscapes (11 Aug 2022)

plantnoobdude said:


> What were the plants you had that required co2? In my experience and research. almost all plants grow well without co2. In my experience the only plant that truly requires co2 in my tank  is eriocaulon quinquangulare, I have not seen any examples of this plant grown in Low tech on the internet either.


Hard to say, it was a while ago now, perhaps:
Eriocaulon cinereum​Or something similar at least, spiky round ball with stalks.


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## plantnoobdude (13 Aug 2022)

goldscapes said:


> Ok, @_Maq_ and @erwin123 there don’t seem to be any obvious supplies of Eriocaulon ‘Vietnam’ or ‘Japan’ in the UK. So I removed the Kyoto and replaced it with some Anubias and C. Helferi I had spare from my other tank. I was careful to keep the rhizomes out of the substrate so hopefully everything will take nicely.
> 
> View attachment 192490


Too late?









						Eriocaulon Vietnam
					

While beautiful, this plant is not easy to grow. It needs an acidic substrate, soft water, and a high amount of light and CO2 injection. It needs a balanced nutrient content, including nitrate, phosphate, iron, and micronutrients. In fact, due to these tough requirements, some hobbyists grow the...




					www.scapednature.com
				














						Tropica 1-2 grow Eriocaulon Vietnam
					

Tropica 1-2 grow Eriocaulon Vietnam  This is a great beginner plant and is new to the hobby in 2019. Found in the Vietnamese area of Thank how, it’s considered a medium sized plant which grows up to 30cm in perfect conditions. This grass like plant is OK in slightly harder water and medium...




					www.horizonaquatics.co.uk
				




Perhaps a back up for the helferi? Some people seem to have issues with converting.


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## seedoubleyou (13 Aug 2022)

plantnoobdude said:


> only plant that truly requires co2


So to clarify. You’re saying that there’s only one plant within our hobby that needs Co2 and all the advice and experience given by others is nonsense as our tanks don’t need Co2.
You’ll have to forgive my naivety on this, why would the likes of ADA, Green Aqua, even George Farmer and others out here advocate for it then?
Are they missing something?

@_Maq_  as already asked, do you have some solid photographic evidence  of what you have achieved within the hobby, running your tanks without Co2? It would be interesting to see.


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## plantnoobdude (13 Aug 2022)

seedoubleyou said:


> So to clarify. You’re saying that there’s only one plant within our hobby that needs Co2 and all the advice and experience given by others is nonsense as our tanks don’t need Co2.


I did not say that… please see my comment
_“In my experience the only plant that truly requires co2 *in my tank* is eriocaulon quinquangulare,” _

There’s a difference between the need for co2 and the fact that all plants will benefit from it. If you say anubias don’t require co2 injection, that is true, though they still will benefit from it.


seedoubleyou said:


> and all the advice and experience given by others is nonsense as our tanks don’t need Co2.


please do not put words in my mouth, I only said that the majority of plants do not *need *co2 injection to grow.


seedoubleyou said:


> would the likes of ADA, Green Aqua, even George Farmer and others out here advocate for it then?
> Are they missing something?


No, they are not missing anything, co2 injection invariably leads to faster growth (providing other growth parameters are sufficient.) this is perfect for those that want “high turnover” tanks where they are pumping out scales quickly and whipping them into shape for whether it be content, or contest. I my self grow using injected co2. I use co2 because I want to get the absolute best out of my finicky and demanding plants, but for a nature scape with a few stems, crypts and a simple carpet, co2 simply isn’t necessary.

If you want examples of what can be accomplished without co2, just look at sudipta’s tanks.


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## seedoubleyou (14 Aug 2022)

plantnoobdude said:


> I do agree


@_Maq_ said Co2 is 


_Maq_ said:


> absolutely unnecessary


and you agreed, so I’m not putting word into your mouth mate, you wrote them yourself.

I’m just trying to understand.


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## Yugang (14 Aug 2022)

seedoubleyou said:


> I’m just trying to understand.


There are many roads that lead to Rome



plantnoobdude said:


> For the vast majority of plants, co2 is completely unnecessary.


vast majority = probably 95%?

The key here is light. When we're flooding our tanks with high intensity light (copy some of the trend setters in the hobby?), it will lead to disaster unless we give the plants enough CO2 and nutrients to grow fast, and outcompete algae. 

Taking a step back, modest lighting, it all becomes much easier and also CO2 becomes much less critical.

Under  low/medium light, tanks are less demanding, more stable and less trouble.  Plants will adapt their CO2 capture enzymes (Rubisco) to accomodate and feel happy (be it at lower growth rate).

The other thing is stability and distribution.
Some of the best in the high tech hobby have stated that the far majority of problems are CO2 related. So when we fire the tank up with high light, high CO2, expertise and dilligence will be key to keep our muscle car on the road.
Lower light and lower CO2 is easier but stability still really important. IMO better do low tech, without CO2 injection, than poorly controlled CO2 injection.


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## seedoubleyou (14 Aug 2022)

Yugang said:


> There are many roads that lead to Rome
> 
> 
> vast majority = probably 95%?
> ...


Great explanation, could starting a tank out “hi tech” to get it to a mature look faster, then dialling it back be a method?


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## Yugang (14 Aug 2022)

seedoubleyou said:


> Great explanation, could starting a tank out “hi tech” to get it to a mature look faster, then dialling it back be a method?


Dialling back, ie reducing CO2 is challenging for the plants. Even more so than dialling up. While reducing CO2  plants need to adapt (produce more of the Rubisco enzyme), which is an expensive process for them with potential complications (temporal slow growth, stunting, or worse). So you may end up setting two steps forward, then three steps back.

Also for the user, balancing light CO2 and ferts is a time consuming process. Even more so when aiming to dial up, then down again.

Patience does more than tech in this case.


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## _Maq_ (14 Aug 2022)

goldscapes said:


> Interesting difference of opinion between the two sites though, any tips for successful growth?


Most websites provide how-to-guides which seem fairly worthless to me. They all take for granted that you inject CO2. With that, their recipes can be summarized as 'A LOT' - a lot of light, a lot of CO2, a lot of macronutrients, a lot of microutrients, and if the plant roots in the substrate, it should be rich in nutrients. And that's that.


seedoubleyou said:


> @_Maq_ as already asked, do you have some solid photographic evidence of what you have achieved within the hobby, running your tanks without Co2? It would be interesting to see.








Unfortunately, that tank does not exist any more. I do have some recently established tanks, and some rather demanding plants live in them. Yet I don't take it as a proof of anything. They 'survived' merely two months, so I don't dare to expose them as an example of success.


seedoubleyou said:


> You’ll have to forgive my naivety on this, why would the likes of ADA, Green Aqua, even George Farmer and others out here advocate for it then?
> Are they missing something?


They care not to 'miss' customers. Keeping plants without CO2 is much more demanding. You have to be diligent to meet given species' demands. It is often difficult to keep all in one tank, within the same environment (pH, alkalinity). You must keep the conditions stable, keep low organic content (i.e. few fish, not over-feeding, etc.), keep high oxygen. The plants grow rather slowly and any event can make damage which takes months to rectify. Obviously, it requires patience and a degree of experience which majority of hobbyists never attain. Bad for business.
Fortunately, you can overcome most difficulties with CO2 injection. CO2 means energy, and with plentiful energy, plants can withstand many adversities. They grow quickly and if you do anything wrong, they will quickly cure. Besides, you can keep almost all species in one tank. In short - you may possess much less expertise, and your results will still be quite good. And with more lighting and CO2, plants create less chlorophyll, so they become super-bright red (most people consider it beautiful).
That said, it often strikes me that many hobbyists present here their tanks, keeping quite undemanding plants, seemingly not aspiring to keep demanding species, and still bother with CO2 injection. Why? It costs money, it makes plants grow super quickly, so you have to permanently maintain your scape, and fish and shrimps would prefer living without excess CO2. The tank of @goldscapes looks exactly like that.
In such cases, I put the question: Why CO2 injection?


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## Hufsa (14 Aug 2022)

_Maq_ said:


> And with more lighting and CO2, plants create less chlorophyll, so they become super-bright red (most people consider it beautiful - just like kids love clowns).


This comment could be interpreted as somewhat inflammatory @_Maq_ , im not sure if this was your intention. It comes across to me like you are comparing most people to kids and saying their red plants look analogous to clowns? Maybe you were just trying to make a point, but if this is what you meant then im not sure this is conducive to polite discussion 😕


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## _Maq_ (14 Aug 2022)

Hufsa said:


> This comment could be interpreted as somewhat inflammatory


Thank you. Edited out. 😓


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## goldscapes (14 Aug 2022)

_Maq_ said:


> That said, it often strikes me that many hobbyists present here their tanks, keeping quite undemanding plants, seemingly not aspiring to keep demanding species, and still bother with CO2 injection.


I appreciate your comments and I am enjoying the debate. You’re kind of missing the point here though. I have aspired to keep more demanding plants, but due to lack of experience none of them has survived, it’s only the undemanding ones that remain.
The more I learn about the hobby I think my initial approach of trying a “medium tech” tank with low light and CO2 was a bad grounding. I may have had more luck sticking with either low or high tech from the get go.

There seem to be three ways I can continue from here:
1) slowly reduce the CO2 until it is no longer required risking the problems highlighted by @Yugang
2) upgrade the light and slowly increase the intensity, maintain the CO2 at safe levels for the fish, and increase the nutrients appropriately.
3) continue with the fairly balanced tank I have at the moment and look to make changes when I switch it out for a larger one.

Option 1 is attractive because I may not have space in my next cabinet for the CO2 canister and running a low maintenance tank is appealing.
Option 2 is equally attractive because even though maintenance demands would increase so would my experience.
Option 3 concerns me slightly because if I change the parameters too much when I move to a new tank then it could take a lot longer to achieve balance.


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## Yugang (14 Aug 2022)

goldscapes said:


> There seem to be three ways I can continue ppfrom here:


It's hard to make choices for us hobbyists, therefore one addition
Option 4: Option 1 + Option 2 + Option 3


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## seedoubleyou (14 Aug 2022)

Appreciate all the information, in summary, it seems that whilst it’s possible to keep plants without Co2 there is no real benefit to be gained as you’re faced with slow growing, finicky and fragile plants.
So the “average” hobbyist like myself if probably better off with Co2 injection.


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## Yugang (14 Aug 2022)

seedoubleyou said:


> Appreciate all the information, in summary, it seems that whilst it’s possible to keep plants without Co2 there is no real benefit to be gained as you’re faced with slow growing, finicky and fragile plants.
> So the “average” hobbyist like myself if probably better off with Co2 injection.


Not all will agree, and not sure if someone talked down the potential of low tech tank. A real large percentage of hobbyists, including real plant specialists, on this forum is happily keeping low tech, no CO2


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## John q (14 Aug 2022)

goldscapes said:


> Just coming round to updating this after 3.5yrs of no posts! Can’t believe how time has flown by.





goldscapes said:


> There seem to be three ways I can continue from here:



Not going to get into the "do I ~ don't I need CO2 debate." What I will say is go with your gut instinct and do what feels right for you. You've been running this tank for almost 4yrs which is far longer than most people keep their tanks/scapes going for, and up to now you seem to have made the right decisions. 👍


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## _Maq_ (14 Aug 2022)

goldscapes said:


> The more I learn about the hobby I think my initial approach of trying a “medium tech” tank with low light and CO2 was a bad grounding.


_My opinion_: If you truly want to learn plant-keeping, you'd better do it low-tech. You'll learn that the most important thing is cleanliness - meaning keeping organic pollution low and oxygen high. When you manage this, you'll get THE plant-keeper. Such is my creed.*
*) Unfortunately, we live in times when most hobbyists think differently.


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## plantnoobdude (14 Aug 2022)

Yugang said:


> vast majority = probably 95%?


I’d say even more tbh.
Off the top of my head I can only think of a handful of plants I haven’t seen growing in Low tech.
Syngonanthus white stripe
Eriocaulon quinquangulare
Rotala macrandra variegated
Ludwigia white
Platinum glosso.
Hygrophila chai

Most of these are chlorophyll reduced mutations, which means they need that extra help from co2, as for Eriocaulon quinquangulare, it is horribly inneficient at using co2, since they cannot use hco3.


I’ll finish my comment with a lovely vase I kept a while back, for most of its life it had tropica soil, high light and no co2.


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## sparkyweasel (14 Aug 2022)

_Maq_ said:


> Why do you folks always inject CO2


We don't.


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## Andy Pierce (15 Aug 2022)

sparkyweasel said:


> We don't.


This is true.  I have one CO2 injected tank (Current setup - Fireplace aquarium) and one not-CO2-injected tank (Shrimphaus - Fireplace aquarium).  In some ways I prefer the non-injected tank.  There's a certain simple rhythm to it with weekly water changes and daily (probably unnecessary) EI ferts.  There's the niceties of not worrying about something going wrong and killing all the livestock or the environmental shame of disposable CO2 cylinders (3 per year - no I won't switch to refillable so please don't ask).  With a low tech tank though, you're playing the long game for sure, which I also appreciate.  I woudn't remove CO2 from my high tech tank mostly because all the sunk costs of having installed the CO2. 
My experience might be typical:  start off deciding to do a planted aquarium and start off low tech for cost reasons.  Then when plants don't do well right away put in the CO2 to 'get things moving'.  Want planted tank RIGHT NOW!  Now that I've learned some patience, I'm ready for a low tech tank, but learning that patience took time and experience.


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## Yugang (15 Aug 2022)

_Maq_ said:


> Why do you folks always inject CO2


There is no way convincing @_Maq_ without data and ratios 

Poll: what level of tech do you have/prefer?​
I used to have a 400 l low tech tank, a couple of decades ago, and also then it was all about the plants for me. I may one day convert my tank and try low tech again, and just experience if there is anything I miss when not using CO2.


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## erwin123 (15 Aug 2022)

My  low tech tank seems to benefit from surface agitation, water circulation and gas exchange. In other words, even if I'm not injecting CO2, I'm still looking at improving gas exchange. 
The disadvantage is massive water evaporation and having to top up water daily.


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## Hanuman (15 Aug 2022)

Lean vs EI, now this.


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## Yugang (15 Aug 2022)

Hanuman said:


> Lean vs EI, now this.
> View attachment 192556


If we ever came to conclusions or consensus on UKAPS there would be no fun left for future generations. We're doing good sofar...


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## PARAGUAY (15 Aug 2022)

Think a lot of us are like @Andy Pierce  because the time and maintenance with CO2 injection is needed but as MD Fish Tanks  says(30odd low energy tanks) pressurized CO2 takes it to another level ,proof of this some of the Journals on here, and the showroom at Aquarium Gardens. But not saying we can't have great tanks without CO2 proof also in the Journals on here


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## _Maq_ (15 Aug 2022)

plantnoobdude said:


> as for Eriocaulon quinquangulare, it is horribly inneficient at using co2, since they cannot use hco3.


Eriocaulons are known to gain substantial share of CO2 through their roots - they oxidize rhizosphere and exude some sugars to attract bacteria & take up CO2 from their respiration. I suspect E. quinquangulare is particularly dependent on this due to low chlorophyll. When planting into a tank, roots suffer and cannot function properly. That's why this species quickly dies. 
This hypothesis could be proven in such a way that someone keeping this species with CO2 injection quits it. I haven't had an opportunity to keep E. quinquangulare yet, I'd like to but it's quite difficult to get, and for a prohibitive price only. 


PARAGUAY said:


> pressurized CO2 takes it to another level


It depends, you know. People tend to believe that there's a non-disputed ideal of beauty. Some expose many species brightly coloured and neatly arranged - in a word, underwater gardens. Others create aquascapes which resemble _landscapes_ more than anything else. For some reason - unknown to me - I happen to not like such creations very much & they are definitely not my goal. I think my perfect tank would look like that you'd doubt whether it had ever been touched by a human hand. A 'natural mess', maybe. For that, too many tubes, pipes and hoses are disturbing. Brightly red plants should be an exception, at most. For that, CO2 amendment is not required. Neither strong lighting. Nor rich fertilizing. It should not emanate brightness, labour and perfection, rather neglect and tranquility.


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## dw1305 (15 Aug 2022)

Hi all,


_Maq_ said:


> . It should not emanate brightness, labour and perfection, rather neglect ..............


I've mastered <"that look">.



_Maq_ said:


> and tranquility.


If only keeping <"tiny, tabby fish"> that you very rarely see counts? That as well.




cheers Darrel


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## Hufsa (15 Aug 2022)

_Maq_ said:


> I think my perfect tank would look like that you'd doubt whether it had ever been touched by a human hand. A 'natural mess', maybe. For that, too many tubes, pipes and hoses are disturbing. Brightly red plants should be an exception, at most. For that, CO2 amendment is not required. Neither strong lighting. Nor rich fertilizing. It should not emanate brightness, labour and perfection, rather neglect and tranquility.





dw1305 said:


> I've mastered <"that look">.









Im so sorry I tried keeping to my journal but I just couldnt resist


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## Hanuman (16 Aug 2022)

_Maq_ said:


> I suspect E. quinquangulare is particularly dependent on this due to low chlorophyll. When planting into a tank, roots suffer and cannot function properly. That's why this species quickly dies.


Yes they are sensitive plants but in my experience less so than some other eriocaulon sp that I have grown. They can melt but are in fact more resilient and can be brought back to life. This is not the case with for example E. ratnagiricum. Once it starts melting, there is no coming back. At least that's my experience.

Back to the E. Quin. In fact an uprooted and replanted E. quin will have most, if not all, its original roots rot eventually and the plant will create new ones. This plant like many eriocaulon, also requires a clean substrate. This is very obvious when uprooting a E. Quin from a dirty substrate and one from a substrate that is clean. The one from the clean substrate will have bright white roots while the other one will have yellowish and rotting roots.


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## Yugang (16 Aug 2022)

I am referring to the Tropica website:





						The right aquarium plants - Tropica Aquarium Plants
					

The right aquarium plants




					tropica.com
				




Tropica says _"Aquarium plants require nutrients to grow. The main nutrient is CO2, which is also the main inhibitor of growth in the plant aquarium. If you don’t add extra CO2, plants have to do with what is naturally released by fish and bacteria inside the aquarium, which is inadequate for plants of the categories MEDIUM and ADVANCED"_

Would we generally agree that for the "Medium" and "Advanced" plants it is highly recommended to have CO2, or is Tropica too cautious here?

Ideally we would have a simple overview which plants are good to go for low tech, and which plants only work with expert care under low tech conditions. I suggest Tropica's site is a good starting point for that.


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## Hufsa (16 Aug 2022)

Yugang said:


> Tropica says _"Aquarium plants require nutrients to grow. The main nutrient is CO2, which is also the main inhibitor of growth in the plant aquarium. If you don’t add extra CO2, plants have to do with what is naturally released by fish and bacteria inside the aquarium, which is inadequate for plants of the categories MEDIUM and ADVANCED"_
> 
> Would we generally agree that for the "Medium" and "Advanced" plants it is highly recommended to have CO2, or is Tropica too cautious here?


That would be a very big asterisk on that for me, they have Bolbitis in the Medium category afaik and it definitely doesnt need CO2


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## erwin123 (16 Aug 2022)

Rotala Wallichii is classified by Tropica as advanced and it grows like a weed in my low tech.

The best starting point for which plants are ok for low tech are UKAPS low-tech journals!


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## Ria95 (16 Aug 2022)

Maq said:
			
		

> Why do you folks always inject CO2 even when it's absolutely unnecessary, only leading to a too rapid growth, and even when the tank is obviously fish-oriented like this one?


How do you know we common folks always do? How do you know it's 'absolutely unnecessary' for someone else's goals? Why do you assume growth is 'too rapid' for their tank?
Always interesting  when such lovely people  ask 'how dare you do what you want with your tank and money?' and demand you explain yourself to them. Here, I  just added 20 ppm NO3 to the  tank, puzzle over that.


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## Hanuman (16 Aug 2022)

Ria95 said:


> Here, I  just added 20 ppm NO3 to the  tank, puzzle over that.


Damm, you are savage! But less than me. I used to add 25ppm 😂


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## _Maq_ (16 Aug 2022)

Ria95 said:


> Always interesting when such lovely people ask 'how dare you do what you want with your tank and money?' and demand you explain yourself to them. Here, I just added 20 ppm NO3 to the tank, puzzle over that.


You've exposed me. I confess: my aim was _to provoke a discussion_ on this topic. It seems I've succeeded in it.
If you take it personally,* I sincerely apologize*. It was not my aim to criticize anyone. And in that particular case - originally, it was a comment regarding certain tank - it was my opinion, and the original poster _asked_ the community for comments.


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## Hanuman (16 Aug 2022)

I knew this thread would be pop corn worthy. I nailed it. 🥳


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## PARAGUAY (16 Aug 2022)

There isn't one size fits all in this hobby l can like a low tech plant heavy look, a IAPLC contest tank/s, a Biotope tank possibly not a lot of plants blackwater. UKAPS is to blame!


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## Ria95 (16 Aug 2022)

Hanuman said:


> I knew this thread would be pop corn worthy. I nailed it. 🥳


Be sure to still have some when the  summary equation describing photosynthesis is revealed / the  climax of the story.


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## _Maq_ (16 Aug 2022)

Yugang said:


> Tropica says _"Aquarium plants require nutrients to grow. The main nutrient is CO2, which is also the main inhibitor of growth in the plant aquarium. If you don’t add extra CO2, plants have to do with what is naturally released by fish and bacteria inside the aquarium, which is inadequate for plants of the categories MEDIUM and ADVANCED"_
> 
> Would we generally agree that for the "Medium" and "Advanced" plants it is highly recommended to have CO2, or is Tropica too cautious here?


I believe all plants without exception benefit from CO2 amendment. CO2 enhances photosynthesis, photosynthesis creates sugars, and sugars are the source of energy to remedy all adversities the plant may face. However, when it comes to sorting plants into easy, medium, and advanced, it is questionable whether CO2 is the right measure to decide. Let me convey some notes regarding selected plants which Tropica ranks among 'advanced', or are generally considered 'difficult':
_Elatine hydropiper_. Definitely can grow without enhanced CO2. Yet it's difficult to establish it because it's so tiny a fragile.
_Bacopa myriophylloides_. Quite the same. It's very very frail, and any physical damage is a point of entrance for microbes. Once established, it's quite undemanding, preferring acidic water and lean dosing.
_Eriocaulon cinereum_, etc. Slow grower. It takes time before it creates a leaf, and it takes hours to lose the whole plant because of organic pollution or for whatever reason. Obviously, if you make it grow faster through CO2 injection, your chances are better.
_Glossostigma spec. Hemianthus spec_. Even easier to establish than _Elatine_. But prone to algae infestation. Also, high levels of oxygen are a must, otherwise they melt from the bottom and get messy. Thus, you need to keep your tank very clean, and if you do, you don't need high CO2 nor very strong lighting.
_Ludwigia inclinata_ Cuba. It can grow quite well in acidic water with lean dosing. The thing is that it seldom shows its full beauty without truly strong light, which is hardly recommendable without CO2 injection. So, is it really difficult, or not? To me, it's not, as I'm quite content with its look as I've got it - narrow leaves of yellowish colour (and _without_ chlorosis due phototoxicity).
_Proserpinaca palustris_. From time to time, it suddenly melts for reasons unknown to me. I suspect - again - that it's sensitive to organic pollution. Apart from that, an easy plant, and quite willingly getting reddish.

I could go on... I believe large majority of aquarium plants can be kept successfully without CO2 injection. The main disadvantage of low-tech - in my eyes - is that to keep various species, you need to learn and follow meticulously their preferences regarding environment (pH, alkalinity, nutrient ratios, substrate qualities, a.o.) and, as a result, you cannot keep all of them in a single tank. Beside that, you have to keep high oxygen and low organic content, which does not fit well with keeping more than just a few small fishes. These are apparent limitations. However, this is *UKAPS* community, so subjecting everything else to plants' health and prosperity is an admissible approach, I assume.


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## Yugang (16 Aug 2022)

Ria95 said:


> summary equation describing photosynthesis is revealed


Don't waste time, go for it. This could be the basis for a  warm friendship  between @_Maq_ and @Ria95 🥰


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## Ria95 (16 Aug 2022)

Plenty of popcorn to go. Besides it got to the stage where 'CO2 enhances photosynthesis'... super saiyan 2  photosynthesis, maybe there's something to this technique.


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## _Maq_ (16 Aug 2022)

Ria95 said:


> Plenty of popcorn to go. Besides it got to the stage where 'CO2 enhances photosynthesis'... super saiyan 2  photosynthesis, maybe there's something to this technique.


Excuse me, my poor English does not allow me to grasp what you want to say.


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