And to add to this keep in mind that CO2 in the form of microbubbles is more efficient for most plants. So even if you have say 10 ppm of co2 and a bit of mist (bubbles) this will be more effective than 100% dissolution in water as obtained via a reactor for example.
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What exactly causes BBA?
- Thread starter Zak Rafik
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Marcel G
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Oh, so many new posts! Jose, I have a question on you: Please, can you give me a list of the "hard to grow" aquarium plants? I plan to do some experiment with the growth rate at different nutrient levels, so I may put them on my list also.
oviparous
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- 9 Mar 2015
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High flow helps because it decreases the boundary layer on the leaf, thus making it more effective to take up CO2.
I've seen figures that indicate that without flow, but with the same CO2 concentration, plants grew a few times slower.
Submerged leafs are much more effective than immerse leaves at CO2 uptake. That's why submerged leaves don't need the same CO2 concentration as in the air to have good growth.
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Marcel G
Guest
Do you know anyone by name who did try to grow different kinds of plants at different CO2 levels through trial and error, and found out that 30 ppm is best? And does he or she documented it for us to see if he or she did it in the right way? How should I know that 30 ppm is best concentration for my plants? If someone found that out, why do you believe him/her? Did you try to grow different plants under different CO2 levels? And in case you did, how should we know that your failure (I suppose you were not successful in that because otherwise you won't opose me in saying that it's absolutely possible to grow healthy plants under low CO2 levels and high light) was caused by low CO2 alone and not some other factors?
I know that T.Barr said once that 20-30 ppm of CO2 should be non-limiting concentration for our plants. The problem is that I don't know how did he get to these values. Why he's not willing to "uncover" his methodology? Does he hide something? Did he do his experiments in the right way? You say, Jose, that you need to be critical to me; but are you critical to T.Barr also? Did you know what are all his theories based on? Did you, for example, know that his EI method was based on misinterpretation of scientific data by Gerloff and Krombholz? I'm glad if you discuss with me about things we both love. But I would be much more glad if you discuss it in the same (critical) way with T.Barr and others also.
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Marcel G
Guest
Exactly! Once I thought that there are "true" aquatic plants, and some "false" aquatic plants which are not adapted to live underwater all their life. But this seems to be a nonsense. There are no true vs. false aquatic plants. There are plants with aquatic (submersed) leaves and plants with aerial (emersed) leaves. Plants with aquatic leaves have very thin cuticle (and sometimes the cuticle is missing completely) and are well adapted for life and for effective nutrient uptake underwater. Plants with aerial leaves are well adapted for life above water, so they have thick cuticle and other terrestrial adaptations (like pores). If you put a plant with aerial leaves underwater, it's hard for it to effectively uptake nutrients. For this kind of plants much higher nutrient concentration are needed to ensure good growth. But once these plants transform their leaves into well adapted aquatic versions, the nutrient uptake efficiency will equal (match) to the nutrient uptake efficiency of other aquatic (submersed) plants. There are very small differences in cuticle thickness between stricktly submersed plants (the ones that are not able to live outside water) and aquatic versions of terrestrial plants.
So I would really like to know what are these "hard to grow species" which would require extreme concentrations of nutrients to grow well (and which are not able to grow well under low CO2). I know of plants which are not able to uptake bicarbonates, but instead they can only utilize carbon in the form of free CO2 (some plants can utilize bicarbonates also, so if free CO2 runs out, they can still get carbon from bicarbonates). But I don't know of any plants which would require some extreme concentrations to grow well. I hope Jose will give me the list.
pepedopolous
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karla
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Hi, the arguments are all great fun. The best looking tanks I ever did myself were all super high light about 6-7 watts per gallon and obscene amounts of co2 . Most want quick growth big plants and rich Color all the methods I've tried, only with high co2 and loads of light came anywhere near of this goal. Excuse poor English very tired and phone is a pain to use.See, wrong again!!!
Hi Ardjuna
well I know this is very unfair from my side to ask someone else to do something but I really havent got the resources, space or anything to do this tests.
Here is tropicas list of harder plants. Could you consider trying out the ones under Pogostemon estellata. Also didiplis diandra is a good one and also any red plant that you want.
If you do this experiment and document it and plants grow well at around 10 ppm of co2 without nutrient limitation, then youll have me with you because this would be a great breakthrough not needing 30ppm of co2.
Whatever I can help with I will.
well I know this is very unfair from my side to ask someone else to do something but I really havent got the resources, space or anything to do this tests.
Here is tropicas list of harder plants. Could you consider trying out the ones under Pogostemon estellata. Also didiplis diandra is a good one and also any red plant that you want.
If you do this experiment and document it and plants grow well at around 10 ppm of co2 without nutrient limitation, then youll have me with you because this would be a great breakthrough not needing 30ppm of co2.
Whatever I can help with I will.
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Rahms
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- 19 Oct 2013
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- 310
did you miss this?
http://tropica.com/en/plants/search/?mode=search&sew=&dif=Advanced&pgr=&ori=&use=
😛
I've just bought some wallichii for my tank..... oops
sciencefiction
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- 26 Feb 2013
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- 3,406
I read it and it still doesn't mean much to me. Even my low tech tanks do better with more light contrary to what I read around and plants suffer if the light is reduced so it's not just co2 that plays a role in those "best looking tanks". So the way I read it is that if you put 6-7 watts per gallon(of what type of light) you need to pump obscene amounts of CO2(how much exactly and how did you measure the dissolved co2 that is indeed available to plants?) and you get the best looking tanks that's you've done(about which I won't argue, they probably are)
From all those "arguments" to me it seems that the biggest problem is that it's hard to dissolve and distribute the co2 in a way so that most if not all of that pumped co2 doesn't just pass by and out the door before the plants have got a glimpse at it. Most people just presume on given tables and ph profiles what the co2 level is but in fairness no one knows for sure or do we? And then again we argue that higher than this or lower than that is best. Maybe the 30ppm you pump in actually gives you a stable 10ppm? 🙂
Is there a way to measure for sure the amount of dissolved co2 in water that is available to plants in a particular aquarium near a particular plant?
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Marcel G
Guest
That's good point. Of course, there can be some differences in the CO2 concentration throughout the tank. As T.Barr already pointed out in barrreport.com, at filter outlet the CO2 concentration is much higher then in other parts of the tank. And in plant beds it may be even lower, as the water is hardly moving there. But that's the case even in the natural rivers. So if in some rivers with lush plant vegetation the CO2 concentration is 10 ppm in the main flow, then at the plant beds the concentration will be much lower.
Besides, right now I have Rotala wallichii in one of my tanks, where I use about 15 ppm CO2. Amano also did grow Rotala wallichii under 9-12 ppm CO2 (according to his Nature Aquarium World books). Jason Baliban also did grow many plants under 10 ppm CO2 and low nutrient levels in water column (with nutrient rich substrates). So it's perfectly possible to grow even the most demanding plants under relatively low CO2 concentration. Of course, if you want maximum growth rate (100%) you are better to use 30-40 ppm CO2, but if you are fine with 50-90%, then your plants may need only 10-15 ppm. I think there's not much difference between 10-15 ppm vs. 30-40 ppm. Personally, I don't prefer all my plants to grow like mad, so that I need to trim them each week or two. I feel better when my plants grow rather slowly, and I don't need to care of them so often. Most aquascapers would prefer slower growth ... once all plants are in the desired shape. Most plant sellers (e.g. T.Barr) prefer faster growth to sell more plants and make more money.
Maybe, one day I'll do the tests myself so that we can know for sure... But right now I focus on other nutrients' (not CO2) impact on the growth rate.
-But how can we explain the so called CO2 defficiencies we see so often then Ardjuna? We know CO2 fixes them.
-Also Amano uses co2 bubbles which again leads to another of Barrs theories. CO2 bubbles can be utilized better by plants than dissolved CO2.
-I think softwater is more important here than most experts say.
- If you ever get to do this experiment it would be nice to do one more thing: Once your plants are growing perfectly well under 10 ppm co2, then we change your water for very hard water (say 18 dKH) and see if this affects the plant CO2 wise.
Thanks Rahms hehe.
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Marcel G
Guest
I have all the information on my website. Also I plan to make a special website for the contributors (donators) with up to date info, pictures, charts, videos etc. After I finish this experiment (5 months? => I plan 1 month for each plant species test, and 5 plant species in total). I'll publish a summarizing article on my website. I consult the test with prof. Cizkova from the University of South Bohemia (she's expert on aquatic plants). I plan to use 15, 30, 60, 90, and 120 ppm NO3 in each tank (with proportional amount of other nutrients). First, I have to try it with couple of plant species to see if these concentrations are OK. If I found that there is no difference in growth rate between 30 and 60 ppm NO3, then I can lower the concentrations to, say, 5, 10, 15, 20, 30 ppm NO3, or in some similar way. So first, I need to find the upper boundary (limit) at which the plants will grow at their maximum growth rate. Also, I don't know if algae won't be a problem at high nutrient concentrations.
Here's a picture of my setup:
I have 200-250 µmol PAR at the bottom of each tank and 1000 µmol PAR at the water surface. But I plan to lower the light intensity a bit to 100 µmol PAR at the bottom (I use 10W LED chips with a dimmer so its no problem for me). Also I already tried the CO2 dissolving efficiency, and it seems very good (I can have deep yellow dropchecker in there => still I plan to use about 30 ppm CO2 during my experiment). The setup on the picture is not complete yet (I'll use a black divider between the tanks so that the light from the adjacent tanks does not affect the light intensity in each tank).
Me neither because of one thing. Im not sure 30 ppm co2 is enough for 100 micromoles of light.
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Marcel G
Guest
I'll use non-stop CO2 supply in there because in such a small tanks (20*20*40cm = 8*8*16in) it would be hard to keep a stable CO2 if I turn it off at night.
PS: I use 120 µmol PAR in my other tank with 10-15 ppm CO2, and I see no algae there (all my plants are in excellent condition). I don't even add any nutrients into the water column (except some Ca + Mg + PO4 as I use RO water). But I use ADA Amazonia in that tank.
PS: I use 120 µmol PAR in my other tank with 10-15 ppm CO2, and I see no algae there (all my plants are in excellent condition). I don't even add any nutrients into the water column (except some Ca + Mg + PO4 as I use RO water). But I use ADA Amazonia in that tank.
How do you know this plants arent phosphate limitted? even if you add some phosphates its still possible. Dont you think?
