FAQs on Carbon Dioxide and Planted Tanks:
Sources
Related Articles: Carbon dioxide and the planted freshwater
aquarium by Neale Monks, CO2 Canopies,
Related FAQs: CO2
& Planted Tanks 1, CO2 &
Planted Tanks 2, CO2 Canopies, & FAQs on CO2 Planted Tanks: Rationale/Use, Yeast-Bottle Types, Compressed Gas Types, Control/Delivery, Measure, Dangers,
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Mmm, the planet in general (CO2 is quite water
soluble), foods, aerobic respiration; you, pets et al.,
carbonates in the water.
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Planted tank filtration/co2 equilibrium?
4/14/2011
Hello WWM crew!
<Hello,>
Hope you guys/gals are doing great and all is going well. As for
myself, I'm in search of a new adventure, in aquaria of course,
which brings me back to writing to you for a few quick answers if you
could.
<Sure.>
I am planning on setting up a 55 gal. moderately planted tank with no
co2. I have tried a couple plants here and there with my fish tanks
over the years and they never seems to work out, even the so stated low
light, low maintenance, hardy plants. This time, after viewing through
many Amano tanks, got my blood pumping once again'¦
<Oh noes!>
The setup will consist of: 55 gal. tank, T5HO 216 watts light (three
6500k bulbs and one 650nM bulb), approximately 3 inch layer of
eco-complete, a Marineland Emperor 400 HOB filter, and a small in-tank
powerhead with an attached sponge/ceramic noodle canister. So far so
good?
<Sure. But do of course remember that the more splashing, the more
CO2 is driven off. That's why HOB filters aren't a good choice
for these sorts of tanks, though they have been used successfully, I
have no doubt.>
My question is, from research, it seems that as though the HOB filter
is a bad idea, due to surface agitation driving off the limited supply
of co2 in the water.
<Yes.>
Now reading at various info sources, this is true in the case of a co2
injected tank, but with a non injected tank, surface agitation is
desirable?
<Don't see the logic here. The agitation at the surface
increases the surface area of the water, and therefore CO2 will diffuse
from the site of high concentration (the water) to low concentration
(the air). Whenever you add CO2 to the tank, what you're doing is
trying to exceed that diffusion rate by some carefully controlled
amount, so an optimal CO2 concentration is maintained in the water. In
almost all cases, plain vanilla aquaria have less CO2 in the water than
is optimal, so plant growth can be limited by that -- assuming other
factors, particularly light, are optimal. Nonetheless, light is FAR
more often the limiting factor holding back plant growth in aquaria,
not CO2, which is why most people find improving light increases their
success with plants, whereas adding CO2 is the "icing on the
cake" once you've already optimised lighting.>
Reason being is that the limited supply of co2 in the tank will be
consumed rather quickly by the plants, and just like oxygen, co2 from
the atmosphere will be infused into the water, though at low amounts,
until an equilibrium is reached?
<There certainly is diffusion of CO2 between air and water, though
the direction will depend upon which contains the most. But diffusion
will have hardly any impact at all below the top millimetre, if that.
Below that depth, it's circulation of water around the tank by your
pumps that keeps CO2 moving around. Yes, if your plants are
photosynthesising fast they will pull the concentration of CO2 in the
water down towards zero, and yes, that'll cause diffusion of CO2
from the air into the water. But the rate that happens is slow, and in
practical terms, plant growth will usually be held back through lack of
CO2 because the supply of CO2 from the air via diffusion just isn't
fast enough. Hence adding CO2 to aquaria where very fast plant growth
rates are desired.>
Is this true and should it be followed? Basically circulation and
surface agitation desirable in a non co2 injected planted tank?
<Agitation is, broadly, undesirable, at least if you want to
minimise the cost of adding CO2. Of course if you can supply CO2 faster
than agitation allows it to diffuse out into the air, then that
isn't a problem.>
Or should I be looking for an external canister filter where I can put
the return underneath the water line?
<This is the standard approach.>
I doubt it will turn into an Amano creation, but we'll see where it
leads me... Tank will be mostly plants with very little live stock, but
I refuse to have a tank without a Pleco of some sort.. Love those
catfishes and was thinking of an Ancistrus of some sort for this
tank.
<Can work in planted tanks. But do look at things like Parotocinclus
jumbo and Hypancistrus sp. L260 as potential alternatives. Obviously
the more carnivorous genera, such as Hypancistrus, are better bets than
the more dedicated herbivores, such as Panaque.>
Thanks greatly for your time and effort. Hope everybody has a great
year!
<And today is, in fact, Khmer New Year, I'm told.>
Andy
<Cheers, Neale.>
Re: Adding light, plants, and kubotai loaches to
stable 55gal freshwater community; Human-powered CO2 infusion
system! 11/13/09
Hi Neale, and thanks again for the pointers.
<Happy to help.>
UPDATE. I did a lot more reading here and at The Krib (among many other
places). I considered lots of CO2 options. I might still go with
pressurized cylinders someday. I even tried simply exhaling into a
powerhead venturi, but then I settled on an even better, VERY low-tech
solution. It's a variation of something I got here at WWM:
CO2 SOURCE: human respiration (that would be ME)
CO2 RESERVOIR: 55 gal trash bag attached to air lineCO2 DELIVERY:
airline attached to venturi input of Penguin powerhead Scrounging
around the house, I found a water bottle, cut large slits in the sides,
and taped the bottle securely inside one corner of the 55 gal bag with
just the top sticking out. That way I can blow into the bag (via the
bottle top) whenever I want. And when I'm done, I simply cap it.
(Any tube and cork would do.) At night, a timer also turns on my second
filter, a hang-on-the-back, bio-wheel model, Emperor 400,
ADVANTAGES
- IT'S FREE. It uses redundant equipment (the UGF-ready powerhead I
already have) and is effectively free. You don't even need special
air line because I don't think human exhalation breaks down plastic
like purer sources of CO2 would.
- IT'S SAFE and WORRY-FREE. This setup is very forgiving. If my CO2
system fails, my plants simply slow down. Nobody gets hurt. No
end-of-tank dumping to carbonate my tank like a root beer-and-Pleco
float. No regulator to fail. No 2-liter bottle to clog and explode. No
valve to break and asphyxiate me while driving (or turn my tank into a
missile). I don't even have to worry about turning it off at night,
because human exhalant also carries plenty of oxygen.
- NO MESSY LIQUIDS. I don't have to keep a yeast culture (yeast
creatures, fun as they are, are not as rewarding as fish or
plants).
- IT'S NATURAL. I get a kick out of including as many biological
cycles into my system as possible--that's a pure tinkerer's
delight.
DISADVANTAGES (pretty obvious)
- REQUIRES DAILY ATTENTION. Breathe, baby, breathe! But this is easy if
I just remember to breathe into the bag for a few minutes while I'm
pleasantly watching the aquarium.
- THE BAG IS UGLY (but can be hidden behind or underneath the
cabinet)
DOES IT WORK? Most definitely! Yes, it works great! One bag full can
last all day (or maybe two days). I didn't measure the pH shift but
my plants started pearling up right away. Some leaves give off a very
fine stream of bubbles at regular intervals (mostly crypts, swords, and
java fern, with some Egeria and Ceratophyllum). I never saw that before
in my tank! Except for maybe a few minutes (or seconds) *immediately*
after a large water change.
All the best to you and rest of the WWM Crew! --dc
<Sounds a fascinating way to approach this problem, and that it
works is very good to know. You might consider taking some photos and
writing a couple thousand words on what you do. This is precisely the
sort of article I'd love to run (for money!) over at the
Conscientious Aquarist side of the WWM empire. Cheers, Neale.>
Re: Adding light, plants, and kubotai loaches to
stable 55gal freshwater community 11/15/09
Yep! your WWM article was part of my (recent) education on true
aquatics.
Very helpful.
<Good to know this article helped. Hope the remainder of your plant
choices are more successful. Cheers, Neale.>
Re: A host of things: substrates, water
parameters, stocking options 8/22/09
Alright Neale,
<Joey,>
Your response got me thinking about a lot of different options. I may
go for the Amazonian set-up as planned, swapping out M. ramirezi for M.
altispinosus.
<A good idea. Since these cichlids, plus many tetras and most South
American catfish thrive in both soft and moderately hard water,
it's easy to create an Amazonian set-up without the expense of
creating soft water.
With moderately hard water, pH stability is easy to ensure, and your
filter bacteria will operate optimally, since these prefer hard, basic
water.>
I'm starting to be drawn more to doing either a hard water or
low-salinity brackish set-up (around SG 1.003). Then, I can still take
advantage of a live plant set-up, while using my area's water
chemistry more easily, and also keeping some very interesting species.
That all being said, I have a few more questions, based on our previous
discussion, as well as other articles I've read on the WetWebMedia
site:
<OK.>
1) The CO2/CO3 issue: I've read about hard water plants that can
utilize carbonate salts as their carbon source rather than CO2. Would
it still be beneficial to supplement these plants with CO2?
<Yes; while such plants can use carbonate, if given CO2, they
photosynthesise that bit better. Equally, the removal of carbonate
allows pH to change, creating variable pH conditions when day is
compared to night. Note that in places like ponds and lakes, such pH
changes happen and animals adapt to them, so in themselves, pH rises
and falls on a daily, cyclical basis are not intrinsically
lethal.>
It seems to me that adding carbon dioxide would simply use up the
water's carbonate buffer reserve more quickly, making the desired
hard water less hard. Thus, to add CO2 to any useful effect in an
aquarium with high KH would unacceptably change water chemistry. Is
that how it tends to work, or is it not that simple?
<It's complicated, but has been thoroughly worked out now. Do
see here:
http://www.thekrib.com/Plants/Tech/golden-rules.html
I'm not an expert on CO2 fertilisation -- have never used it -- but
would direct you to those good folks at The Krib who really know about
this stuff.>
2) I've got a few different ideas for stocking arrangements for
fish for the hard water set-up, one of which I'd like to run by
you: a school of *Melanotaenia *praecox, two Kribensis (probably
female, to decrease territoriality and prevent breeding--desired for
the time being), perhaps one other which I would carefully
research/choose, and lastly, *Colomesus* asellus. That's the
particularly question-mark fish of the group, of course. I'd really
like to keep about three of them. I know that it is debated whether a
puffer even as peaceful as this one should be kept with other fish,
whether it would be a healthy fit in general. I read the article you
wrote, "The Nice Puffer," and you offered a few words about
this topic. I'm wondering if you can tell me a little bit more of
your opinion on the matter.
<Will depend on the size of the tank: my SAPs are largely well
behaved in a 180-litre system with rocks and floating plants to provide
cover. In smaller tanks, your degree of success may well be
less.>
With the Kribensis, my reasoning is that the SAP won't be as
demanding of the caves as other puffers might be, and thus won't
compete with the Kribensis, and that the cichlids can defend themselves
against nipping.
<Have kept SAPs with a different Pelvicachromis species, P.
taeniatus, and they worked pretty well except for the occasional nipped
dorsal fin.>
I'm hoping the M. *praecox *are active and fast enough to evade
harassment by the puffers?
<Might be, but again, will depend on the amount of swimming space.
Some rainbowfish species tend to sit about in midwater rather than
actively patrol the tank, so think about that when shopping. Big groups
and strong water currents should tilt the odds in favour of the
rainbows.>
Also, are there other fish that would fit into this arrangement
well?
<Pretty much what's written in that article! Have subsequently
found Ameca splendens works well with them, and by extension, you might
consider other feisty Goodeids, such as Xenotoca eiseni.>
I don't know about the puffers. I'm really interested in having
one of the interesting hardwater/brackish oddball groups for the
variety they provide, and I'm very drawn to these SAPs.
<They are great fish. However, Carinotetraodon irrubesco is perhaps
that bit easier to slot into community tanks, and with floating plants
available, spends much time in the open and at the top of the tank,
begging for food.>
Let me know what you think.
Once more, thanks for your help,
Joey E.
<Cheers, Neale.>
CO2 Website Recommendations
2/16/08 Hi, I just wanted to tell you about the setup I have.
I have a 40 gallon display, tall tank with a 6.4 pH and good ammonia,
nitrites, and nitrates, forgot the numbers, but I believe it was low,
and I have very soft water. I have a whisper filter that pumps 100
gallons per hour, and in addition, I have 3 undergravel filters. I use
glass gravel and I have some ornaments and hiding spaces for the fish.
I have the bubble generator to supply oxygen for the fishes. In the
tank, I have 3 live plants, planning on getting 2 more but not sure
what types. I wanted to get a floating plant for the discus, what would
you recommend? <Water sprite would be a good choice to try depending
on your conditions.> I have 3 discus, and 10 cardinal tetras. I keep
the temperature at 82 degrees. Is this overstocked or is it possible
for me to add any more cardinal tetras, possibly 10 more, or is it too
much? <Keep the nitrates under 20 ppm with water changes. Live
plants will help with the nitrates depending on the lighting and
general health of the plants. If you cannot keep the nitrates under
this level then I would recommend not adding any additional fish.> I
do 30 percent weekly water changes and feed them frozen bloodworms,
brine shrimps, beef heart, occasionally, and flakes. I am also trying
to build a carbon dioxide generator, as I saw online. However, there
are so many different recipes for the reaction, which one would you go
with? Do you recommend making one? Thanks so much for your help. < A
good friend of mine runs a website called thekrib.com that discusses
CO2 and the pros and cons of adding CO2. This is not a toy and can wipe
out your entire tank if not used correctly. I recommend reading this
website often and do not use CO2 until you know what you are getting
into. If you do decided to go this route then it will help you build a
CO2 unit with everything you will need.-Chuck>
Planted Tanks... Seltzer water for CO2,
pots... 2/28/08 Thanks For Your Great Website, The
Cream of the Crop ...... <Okay!> I am not new to the hobby, 20
years of Fresh Water Planted & Marine/Reef. Enjoy the hobby so much
I build custom acrylic aquariums/sumps, complete set up in Garage to do
so with all essentials needed for a professional result. <Neat!>
(Police Officer as a Career) I recall as a child, a neighbor with a
planted tank, would replace his evaporated water with Seltzer Water,
Have You ever heard of this? <Gosh... it's been years... but
yes... for the, oh I see this below> I personally don't see the
reason to add CO2 to any of my Planted Tanks (But a firm Believer of
Iron Additives). <Agreed... carbon dioxide is readily available...
from inside and outside tanks... readily soluble in water... generally
not rate-limiting...> I have a RODI Unit that I use as an ATO, but
Always pondered the thought of all the half full seltzer bottles I
emptied into the sink. <? Maybe... smaller bottles, are they going
too-flat for drinks? Can/could be poured in your tanks> Second
Question.. any benefit in leaving potted plants in the pots when
planting? Take Care.. Matt <Mmm, perhaps to save a bit of mess...
some are made to fall apart/decompose over time... By and large I
remove these pots myself ahead of planting. Cheers, Bob Fenner>
Aquatic plants 5/17/07 hello again. <Hello> I
have a new question about Aquatic Plants. I'm thinking about
starting a Garden and seeing some of the pictures online I was and
still am completely amazed by it all. However, I still have a few
questions.... the first question I have is about filtration. Is it
possible that when I set up the tank and the plants that all I could
use would be a bag of active charcoals to help put co2 into the water
system for the plants to feed off of? <Maybe... adding carbon will
in some ways make it available... but gaseous introduction is the best,
surest way of provision> I have looked on the site... but there
isn't a sections for water garden plants for dummies so all the
places I've looked have all these technical words that I really
don't understand. could you help me out please? thanks, Paul <Do
give the Krib (.com) a read as well as Dennerle and Tropica's
sites... perhaps Takashi Amano's books, Pablo Tepoot's one
volume on plants, planted systems... There is, indeed, much to know...
and therefore good reason to invest ones time in study here. Bob
Fenner>
Air pumps, aerating planted tanks -
05/13/2006 I was reading in a book and it said that keeping air
pumps on during the day is not really a good idea... if you have
plants. <Can be detrimental... as this "drives out" Carbon
dioxide, adds oxygen...> It did not really give a reason but it said
that since photosynthesis stops during the night hours, <Actually...
the dark reaction/s of photosynthesis occur during non-lighted
periods...> and everything in the tank gives off carbon dioxide,
that it is a good idea to have an air pump / air stone running at
night. Should I leave air running all day or do what the book suggests.
Thank You <I would likely leave all running continuously... much
more to this "story" then stated here... likely other factors
are much more important to your overall plant growth, health... Too
much chance, possibility of trouble with leaving gear off... Bob
Fenner>
Re: new 72-gallon tank setup Hi Ronni, <Hello again
Paul!> This is Paul writing to you from Toronto, Canada
again. We last talked about a month ago while I was in the
process of setting up my 72 gallon tank. <Yep, I remember> I
finally got my tank running and everything looks like it's going
well. I have a total of 19 fishes and several
plants. Even though my plants are doing okay, I would like
to inject some CO2. There is a product from Germany called
"Carbo Plus" which generates CO2 by
electrolysis. Have you heard of such
product? What is your opinion of it? Do you know
of anyone that have used this product and are fully
satisfied? The apparatus is quite costly and I would like to
get some feedback before investing in it. <Honestly, I've never
heard of it so don't know whether it works well or not but I would
recommend asking about it at http://wetwebfotos.com/talk/ as
someone there is bound to have tried it.> Thanks and take care. Paul
<Sorry I couldn't be of more help! Ronni>
Carbo Plus for Co2 Hi Bob, I have my 72 gallon setup running
for about a month now with several plants and about 20
fish. I would like to add co2 to give my plants a boost by
injecting co2. There are several methods out there and I
have come across a German product called "Carbo
Plus". Have you had any experience with this
product?? Or do you know of anyone who has used this product
and been very successful. The product sounds too good to be
true. Since it's an expensive investment, I would like
to get some feedback first. Thanks for your time to response. Paul
<Have seen this product in magazines and at the international
tradeshow, the InterZoo (in Germany). The science is sound, but I still
prefer CO2 injection... w/ or w/o a meter in concert. Bob
Fenner>
Construction of a CO2 Canopy for Plant Tanks <Interesting
concept. Have you considered submitting this work for pet-fish magazine
subscription? Please do. Here is the name, email address of a friend,
Sue Steele, who acts as the Managing Editor of Freshwater and Marine
Aquarium Magazine in Los Angeles: famamag@aol.com. You may want to
re-do your drawings (for clarity and publication). Will post your name,
article on the Plants Subweb of WetWebMedia.com with your name and
permission. Bob Fenner>
Construction of a CO2 Canopy for Plant Tanks Dear Bob,
<Lalith> Thank you very much for replying my mail. I am so happy
that you considered it as a good project. Many thanks for agreeing to
publish my article in your web site. I will also submit it to
Freshwater and Marine Aquarium Magazine with better drawings. In the
meantime I will contact your friend Sue Steele with the present
document. Once I redo it I will forward it to you. I very much
appreciate your kindness in giving your support to my little work.
<A pleasure my friend. It will be well-received and stir people on
to experimentation, application, considering their possibilities. Could
there be anything better? Bob Fenner> Lalith