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  1. dw1305

    When to use co2

    Hi all, That is why I've mainly gone away from stems, other than <"Ceratopteris thalictroides and Ceratophyllum demersum">. I like plants that grow fairly slowly (Cryptocoryne spp. Anubias, Ferns, Mosses) and then I just have a floating plant (non-CO2 limited) as both my <"canary"> and as a...
  2. dw1305

    When to use co2

    Hi all, It wouldn't be. Just keep things how they are and carry on watching the plants, all the time they (and you) are happy just keep things the same. If plant growth slows add a bit more fertiliser. You could increase growth rate by adding more light, CO2 and mineral nutrients, but you...
  3. dw1305

    Good ph and kh pen?

    Hi all, No, you can't unfortunately. The issue for me is that I wouldn't trust that meter to give you an accurate pH profile. I'm not a CO2 user, so I don't have practical experience of constructing a pH profile during CO2 addition. If you have hard water? you are more likely to get an...
  4. dw1305

    Good ph and kh pen?

    Hi all, It is not ideal, two point calibration would be much better. If I had ~£50 I would spend it on a a conductivity meter, rather than a pH meter. cheers Darrel
  5. dw1305

    Snails and C02 calculations

    Hi all, You can do much better than that in terms of accuracy. You can actually make a known "4 dKH" solution and then use that as a standard to calibrate the Tropic Marin KH test against. You can make an exact 4dKH solution by dissolving 6g of pure sodium bicarbonate (NaHCO3) in DI water and...
  6. dw1305

    Snails and C02 calculations

    Hi all, Terrestrial snails can repair mechanical damage to their shells to some degree. I assume because the dried mucus sticks the shell back together and the mantle can then secrete new shell on the inside of the shell. The calcium carbonate they secrete comes from their food source. They...
  7. dw1305

    Snails and C02 calculations

    Hi all, You've got two different factors. Snails from hard running water, or <"large calcareous lakes"> (like the Nerite and Rabbit snails) will have no physiological adaptations to deal with high CO2, they come from hard water where the Total Inorganic Carbon <"(TIC) is always in the form of...
  8. dw1305

    CO2 gaseous equilibrium with atmosphere

    Hi all, It is 0.6 ppm if you work from <"Henry's Law and the 415 ppm of CO2 in the atmosphere">. We aren't entirely sure where the "3ppm value" came from, but there are threads about how it relates to the <"dKH/CO2/pH chart"> and the <"original 3 ppm reference">. cheers Darrel
  9. dw1305

    Providing 'just enough' CO2

    Hi all, Second hand Eheim filters for me. I've recently found a couple that I have no recollection of buying. cheers Darrel
  10. dw1305

    Providing 'just enough' CO2

    Hi all, Cynical, but if Seachem did the advertising they might be able to sell the ADA bucket for two grand. cheers Darrel
  11. dw1305

    Providing 'just enough' CO2

    Hi all, That one. cheers Darrel
  12. dw1305

    Oxygen diffuser in reverse cycle off c02/lighting period - why wouldnt you...

    Hi all, Unfortunately that has been the problem on some of the other forums I've belonged to. People have been unwilling to accept that plants are <"net oxygen producers"> and have used the fact that low oxygen events occur during the night as conclusive, and irrefutable, evidence that I'm...
  13. dw1305

    Does pearling mean the water is oxygen saturated?

    Hi all, I think if the whole carpet was pearling it would suggest that the water column is close to oxygen saturation. As the others have said oxygen isn't very soluble in water, so localised pearling just tells you that the water in contact with the leaves was fully saturated. It is that lack...
  14. dw1305

    Does pearling mean the water is oxygen saturated?

    Hi all, You can get pearling in sewage works (during <"activated sludge treatment">), if it is sunny. The process involves period of intense churn and then a static phase to allow the solids to settle out. During the settlement phase flocs containing cyanobacteria are buoyed to the surface by...
  15. dw1305

    Oxygen diffuser in reverse cycle off c02/lighting period - why wouldnt you...

    Hi all, It would depend a little bit on which <"photosynthetic pathway"> Blyxa spp. have, but I'm going to assume that they are "C3" plants. You also need to be aware of the <"BOD concept">, because what happens is going to be dependent upon the microbial bioload as well as the density of...
  16. dw1305

    Oxygen diffuser in reverse cycle off c02/lighting period - why wouldnt you...

    Hi all, Yes, it wasn't as well received as I'd hoped at the time, but I think more people have probably come around to it over the ~15 years since I wrote it. I stand by it as a document, although in many ways <"the past is a different country">. It is just the difference between "added CO2"...
  17. dw1305

    Oxygen diffuser in reverse cycle off c02/lighting period - why wouldnt you...

    Hi all, I like extra aeration, realistically you can never have too much oxygen. Have a look at <"Aeration and dissolved oxygen....."> I wrote it specifically for <"Plec keepers">, but it is relevant to all fish keeping. On UKAPS <"Oxygenation via plants"> and <"@Geoffrey Rea 's post">...
  18. dw1305

    Rainwater & CO2

    Hi all, They had really acid water, so nearly all of the ammonia/ammonium is ionized NH4+. You would only need a small addition of oxygen (or slightly warmer temperature) to kill all the fish. Temperature is quite an interesting one, because they are very thermophilic fish, which means...
  19. dw1305

    CO2 bottle replacement while maintaining the exact same regulation

    Hi all, Yes, you are right, pH is stable in carbonate rich (high dKH) water, because of the <"carbonate (HCO3- and CO3--) buffering">. Basically you have to add a lot of acid to before you get any <"change in pH">. You can see buffering in action in @Zeus.'s video post in <"Guide to TDS"> and...
  20. dw1305

    Don't know what to believe

    Hi all, I'm <"not a CO2 user">, but I agree with the other posters, the <"drop checker is likely to be right">, because it doesn't have much margin for error. Nitrate testing <"is quite problematic">, so I don't tend to make <"decisions based purely on test kit values">. If you can get tap...
  21. dw1305

    Where can i get a big bottle of drop checker solution??

    Hi all, This is <"always happening to me">, you spend ages writing a reply and then just before you post it, some-one posted the same thing. cheers Darrel
  22. dw1305

    Where can i get a big bottle of drop checker solution??

    Hi all, Just by weight. Because water has a density of one, a kilogram of water has a volume of one litre and one gram = one millilitre. Even in the lab. I use the scientific balances, rather <"than volumetric flasks">, for most things. I only use a pipette now for very small volumes...
  23. dw1305

    Where can i get a big bottle of drop checker solution??

    Hi all, There is no way of knowing, but my guess is that this is the wrong way around, and that your test kit is reading 5 dKH in a 4 dKH solution. I'd think of it this way. You give me a £1 coin, and rather than accepting it is £1, I weigh it, and say "it weighs as much as £2, so it is...
  24. dw1305

    When is too much CO2, too much?

    Hi all, We have <"a thread">. cheers Darrel
  25. dw1305

    When is too much CO2, too much?

    Hi all, I don't know, my guess would be that you can't practically dissolved enough CO2 into the water to get anywhere near the levels that would cause problems. <"Lake Kivu is supersaturated with CO2 of volcanic origin">, and appears to have aquatic plants growing in it. I couldn't find any...
  26. dw1305

    Co2 Bubbles ruining the experience?

    Hi all, Yes, that would be right, the only proviso is that we don't know what happens <"to the micro/nano bubbles">, they have the potential <"to damage the filter microbes">, but I assume this isn't a problem in practice. cheers Darrel
  27. dw1305

    Co2 Bubbles ruining the experience?

    Hi all, It doesn't make any difference to the aquarium / filter system, because you have the <"same bioload"> (and level of oxygenation) in either case. The advantage of the highly oxygenated water entering the filter is that it ensures that microbial nitrification (the conversion of...
  28. dw1305

    ph drop during co2 injection

    Hi all, Yes, that is <"what we think">. As you can see (from all the <"linked threads">) there is both <"chemistry and uncertainty">involved. cheers Darrel
  29. dw1305

    ph drop during co2 injection

    Hi all, I'm <"not a CO2 user">, so I don't have any practical experience of adding CO2, but I'd definitely <"get a drop checker">, even if you use the pH pen to get a pH profile. cheers Darrel
  30. dw1305

    Bluey greeny yellow...ish

    Hi all, We have a few of these <"long and inconclusive threads">. I'm a <"self-confessed luddite">, but I think it is important that people try new products, even though they may eventually conclude that the advantage they offer doesn't out-way <"their cost"> or inconvenience. My guess is that...
  31. dw1305

    Bluey greeny yellow...ish

    Hi all, You can buy <"bromothymol blue pH indicator"> relatively cheaply via ebay etc. Ebay seller "kitchen-chemistry" are still selling it, ~£6 for 35mL. cheers Darrel
  32. dw1305

    PH accuracy?

    Hi all, Following discussion of Carl Stromeyer in <"another ORP thread">, I've just read his <"Aquarium Redox Balance">, which is a good read. cheers Darrel
  33. dw1305

    PH accuracy?

    Hi all, I agree with @jaypeecee. The other issue is that high ORP isn't an unalloyed good thing in a freshwater aquarium. There is more discussion in <"REDOX why don't we measure it?"> and <"Canford Park">. cheers Darrel
  34. dw1305

    Good ph and kh pen?

    Hi all, There isn't really a <"good cheap, accurate pH meter">. They are quite complicated bits of kit, and you need one with two point buffering etc. Carbonate hardness is a bit different, there <"isn't really a meter for it">, but you can <"measure alkalinity"> via an <"acid base titration">...
  35. dw1305

    CO2 + excessively low PH?

    Hi all, Yes exactly that. The only concern with crushed coral is the environmental one. Oyster shell or cockle shell chick grit (to feed to chickens and caged birds) is just a cheaper option for most people. I use rain-water in the tanks, but I have a good quality hard tap supply, so I can just...
  36. dw1305

    CO2 + excessively low PH?

    Hi all, Because of where you live I'd just go and get some oyster shell. PYO Cuttle "bone" would be another possibility. We've got a few <"sceptical" threads">. You can buy <"Seachem Equilibrium"> or use a <"DIY mix"> of potassium bicarbonate (KHCO3), calcium chloride (CaCl.6H2O) and Epsom...
  37. dw1305

    CO2 + excessively low PH?

    Hi all, It is to do with lack of <"buffering">. You still have soft water (low dKH), but your water company has added a non-carbonate, strong base to raise the pH. Your water company will add <"sodium hydroxide (NaOH)"> to your tap water to raise the pH. They like NaOH because it is cheap and a...
  38. dw1305

    The dissolved gas / bubbles paradox

    Hi all, That should be a start for a search, I'll see what I can find. This one has some details <"Underwater photosynthesis of submerged plants...">(from the <"liquid carbon thread">). I can get full-text, is it available to every-one via the link? cheers Darrel
  39. dw1305

    The dissolved gas / bubbles paradox

    Hi all, They certainly have fewer stomata in the submerged leaves of (potentially) emergent plants. Obligate aquatic plants don't have stomata or a water resistant cuticle. If plants have fewer stomata, my guess would be that that is accompanied by a thinning of the cuticle allowing more direct...
  40. dw1305

    The dissolved gas / bubbles paradox

    Hi all I don't know, but my guess would be that, when you have a mist of CO2 bubbles, some are getting trapped under the leaves etc and then that CO2 is passing straight into the plant via the stomata, or <"direct diffusion"> into the cells in Vallisneria etc. I'm not a CO2 user, but you get...
  41. dw1305

    Liquid Carbon

    Hi all, My guess would be that obligate aquatic plants are much more likely to be damaged by liquid carbon. I think Vallisneria is the one most often mentioned, possibly because it is much more commonly grown than Blyxa spp. etc or possibly because it is more susceptible to damage? Some-one else...
  42. dw1305

    Liquid Carbon

    Hi all, Some "terrestrial" plants will grow indefinitely under-water. Many come from areas where there are regular seasonal monsoons etc. which mean that they are used to periods of emersion/immersion, other will mainly grow underwater, but if they are exposed to the air it will trigger aerial...
  43. dw1305

    Liquid Carbon

    Hi all, It wasn't me directly, but I think it is right. Obligate aquatic plants ("hydrophytes") don't have a stomata or a cuticle ("epidermis") (<"Underwater photosynthesis of submerged plants...">*), because these are mechanisms, that terrestrial plants use, to control water loss. Once they...
  44. dw1305

    Co2 Profile and water changes on new scape

    Hi all, I'm not a CO2 user, but that sounds a plan. I'll cc. in @Zeus. as he has <"practical experience"> and there is @Carpman <"New scape pH profile"> thread as well. I think that is what Tom Barr @plantbrain said, have a look at this one <"amount of CO2....">. This recent thread...
  45. dw1305

    Co2 Profile and water changes on new scape

    Hi all, I'd only use the pH probe with a drop checker, the problem with the alkalinity meter is that it shows all bases, rather than just the carbonate. Once you are happy with pH drop you can use that. The advantage of the drop checker is that you know the fluid is 4dKH and doesn't contain any...
  46. dw1305

    CO2 tuning - need help

    Hi all, That is pretty much it. If you want an analogy it is like a colour photocopier, you can photocopy primary colours and get really good replication, but if you <"photocopy a bank note">* it can't replicate the different tones of brown, mauve, pale green etc. cheers Darrel *(allegedly)
  47. dw1305

    Determination of CO2 in combination with an aquasoil

    Hi all, My guess is extrapolation, and that "30 ppm CO2" doesn't necessarily mean "30 ppm of CO2". The normal CO2 sensor for in situ measurement is a "Severinghaus probe", so I'll see what I can find out using that as a search term. I think I've got it (from <"The measurement of dissolved and...
  48. dw1305

    Determination of CO2 in combination with an aquasoil

    Hi all, That is right, a lot less dissolved CO2 (and all other gases), because of Henry's Law. The question would be has any-one actually measured the amount of CO2 using an <"ion selective electrode">, rather than extrapolating from an acid base titration (which is how both the lamotte test and...
  49. dw1305

    Determination of CO2 in combination with an aquasoil

    Hi all, I still refer back to the Krib. That is where I saw it, there is actually a link in @xim's post in <"Determination of CO2........">, but as far as I know there isn't a scientific reference. Back to why the drop-checker might offer some advantages. Measuring dissolved gases is never...
  50. dw1305

    Determination of CO2 in combination with an aquasoil

    Hi all, It goes down. As CO2 levels rise it changes colour, from green through to red at 2000ppm CO2, at which point it shuts down the gas and electric (but not the students breathing). I'm not sure, to even get to 3ppm dissolved CO2 you need a huge amount in the atmosphere (@Ed.Junior's post...
  51. dw1305

    Determination of CO2 in combination with an aquasoil

    Hi all, Theoretically it is less than <"1 ppm of dissolved CO2">. I never found out whether there was any empirical research indicating where <"the "3 ppm" of CO2 came from">. As alluded to in the link we have a CO2 sensor in the lab., and it usually reads more than the <"~415ppm of CO2">...
  52. dw1305

    Yeast-based CO2 DIY mix using Nutrafin kit

    Hi all, There are a <"few references to using "Jello"> to regulate CO2 production. cheers Darrel
  53. dw1305

    Determination of CO2 in combination with an aquasoil

    Hi all, I'm not a CO2 user, but I think that because the drop checker uses the CO2 ~ HCO3- ~ pH equilibrium, you can change the hardness of the dKH solution (the HCO3- part) to give you the same colour change for less CO2 addition. If you have a 2dKH solution, you should get the pH colour change...
  54. dw1305

    Stable CO2

    Hi all, I think you have to differentiate between low tech and hi tech. In a low tech, the plant mass is going to effectively deplete the CO2 during the photoperiod, you can get a measure of this by the variation in pH (as the CO2:O2 ratio changes). A larger plant mass will deplete that CO2...
  55. dw1305

    1 Year On and Many Fish Deaths

    Hi all, I think microbial nitrification will be reduced at lower pH, but it definitely won't stop. In terms of what we know about nitrification the past is <"definitely a different country">. There are a <"much larger range of organisms"> involved in nitrification than was initially thought...
  56. dw1305

    Stable CO2

    Hi all, In the summertime....... cheers Darrel
  57. dw1305

    Stable CO2

    Hi all, I'm pretty sure that light intensity at midday in the tropics is going to be an order of magnitude larger than anything that we can produce with a lamp. I'll try and find a reference that quotes the different measures of light intensity. For sunlight you should be able to equate light...
  58. dw1305

    Stable CO2

    Hi all, That would be pretty standard for a low tech tank, even with reasonable flow. If you had a situation with lots of nutrients and lower flow, then you could end up <"with even greater variations">. These occur in natural waters as well, where they are described as <"diel" pH variations>...
  59. dw1305

    1 Year On and Many Fish Deaths

    Hi all, @Creature Seeker I'm not a CO2 user, I never have been and I never will be. My opinion is that it presents an unacceptable, and unnecessary, risk to fish health. As well as the ever present risk of catastrophic fish death there maybe long term sub-lethal effects. I know other people...
  60. dw1305

    Bubbler while injecting co2 - hear me out.

    Hi all, I'm not a CO2 user, but that would be the route I went down if I was. You would get a rapid pH rise as the O2:CO2 ratio swung in favour of oxygen, some-one else will have to tell you if that is a problem in practice. cheers Darrel
  61. dw1305

    Bubbler while injecting co2 - hear me out.

    Hi all, You don't need to worry as much about oxygen levels during the photoperiod, unless you have a very small plant mass. Plants are very effective at oxygenation, you can even get <"cyanobacteria pearling in sewage treatment"> when the sun is out. <"A question......"> might also be of...
  62. dw1305

    Does excess co2 inhibit plant growth?

    Hi all, @jaypeecee you might be interested in what Tom Barr (@plantbrain) siad in 2011. In <"Oxygen in a planted tank">. cheers Darrel
  63. dw1305

    Does excess co2 inhibit plant growth?

    Hi all, That was a good one, and definitely better than I could manage. cheers Darrel
  64. dw1305

    Does excess co2 inhibit plant growth?

    Hi all, It is exactly as @Alex C says, they are directly related because the haemoglobin transports both CO2 and O2. There is a full description in the <"fish respiration"> link earlier in the thread. The issue is that at the gills, the diffusion of gases depends upon the concentration gradient...
  65. dw1305

    Does excess co2 inhibit plant growth?

    Hi all, Just keep away from fish from cool, flowing water really. So definitely not Hillstream Loaches. Bit of a funny one really, fish like Pterygoplichthys gibbiceps are very tolerant of low oxygen levels and can take in oxygen from gulped air, against that some of the rheophilic Chaetosoma...
  66. dw1305

    Does excess co2 inhibit plant growth?

    Hi all, Here is the actual one for CO2. cheers Darrel
  67. dw1305

    Does excess co2 inhibit plant growth?

    Hi all, I've also found the graph (that I couldn't find the other day) <"showing the effects of pressure"> on gas (in this case O2) solubility. I would assume that CO2 shows a similar response to increasing barometric pressure. cheers Darrel
  68. dw1305

    Does excess co2 inhibit plant growth?

    Hi all, This subject has come <"up a few times on the forum">, but because you can't search for "CO2", you have to search for terms like <"hypercapnia"> and <"Bohr Root"> effect. I'm not a CO2 user, so I don't have any practical experience of keeping fish at enhanced CO2 levels. It isn't an...
  69. dw1305

    Does excess co2 inhibit plant growth?

    Hi all, It is a very soluble gas, so you can dissolve a huge amount in cold water. Looking at the graph you can get a theoretical maximum value of about 1500 ppm at tank temperatures and atmospheric pressure. Chart from the <"solubility of gases in water">. I guess that is because the more CO2...
  70. dw1305

    CO2 Drop Checker Solution

    Hi all, You can do it all by weight. Because these are fairly dilute solutions you can assume one mL of solution weighs one gram. I know a lot of web sites and advice on the internet pushes water testing, but this is totally the wrong way around, you have a known value, but you are doubting your...
  71. dw1305

    CO2 Drop Checker Solution

    Hi all, I'd probably start again as well. Sodium bicarbonate is <"nice and cheap">, and you really don't want any <"errors with CO2 levels">. I usually <"use a spreadsheet"> for all of these little calculations. The derivation of dKH is actually a <"bit strange">, but the 1.2 g in 1000 mL is...
  72. dw1305

    Broken "special style" neo diffuser

    Hi all Snap (literally) same thing happened to me Friday night, I've never had it happen before in ~40 years of driving. No cars anywhere near me, just heard a noise like a wine glass breaking in the distance, looked down at the driver side wing-mirror and the glass had gone. cheers Darrel
  73. dw1305

    Light has failed, should i turn off c02

    Hi all, Yes. cheers Darrel
  74. dw1305

    Not a good write up for liquid carbon

    Hi all, We have a <"few threads"> like this. I start from a simpler premise, which is that is that if you follow a <"risk management approach"> to fish keeping you are likely to accidentally kill your livestock less frequently. Under that approach, both liquid carbon and CO2 are entirely...
  75. dw1305

    PH monitor suggestions - continual use

    Hi all, I've been thinking about this, and I may be wrong, but isn't there a more fundamental issue, which is that the decimal places on pH values can differ by several orders of magnitude, because pH is a -log^10 scale representation of the hydrogen ion activity? I think that implies that...
  76. dw1305

    PH monitor suggestions - continual use

    Hi all, I'm very interested in how this goes as well. I don't think you will either, but even if it was +/- 0.1 I'd be happy. cheers Darrel
  77. dw1305

    Do water changes cause co2 fluctuation?

    Hi all, It does, but you can ignore it in freshwater. It is relevant for marine fish keepers, where you have much higher levels of dissolved salts. The same applies to air pressure, the differences are relatively minor, unless you live in <"Denver"> etc. Temperature is the thing that really...
  78. dw1305

    Do water changes cause co2 fluctuation?

    Hi all, You don't need to worry, it won't make any difference for dry salts like KNO3 and MgSO4.7H2O, they don't have a sell by date, and are basically good <"for all of eternity">. It could be, if the new leaves look small and pale? then it is likely to be iron deficiency. Iron is different...
  79. dw1305

    Do water changes cause co2 fluctuation?

    Hi all, Not sure then. Has the Rotala grown better in the past? Its new leaves looks a bit pale as well. cheers Darrel
  80. dw1305

    Do water changes cause co2 fluctuation?

    Hi all, Do the plants really look that pale? If they do, it suggests you may have an iron (Fe) deficiency. Iron is difficult to <"keep in solution">. You may have hard water in Dublin, if it comes from a limestone aquifer? or very soft water (if it comes from the Wicklow mountains). Iron...
  81. dw1305

    PH monitor suggestions - continual use

    Hi all, I think the "continual" bit is the issue. Any system that works by the continual leakage of ions is going to give problems long term, so you really need to use a solid state option, and to keep it isolated from electrical interference (like Marcel's @zozo option). You can get "standard"...
  82. dw1305

    PH monitor suggestions - continual use

    Hi all, You need a solid state ISFET probe, if you are going to use it in the tank long term. You also need an ISFET probe where it uses a "reference field effect transistor" (REFET), rather than a silver chloride (AgCl) glass reference electrode. Even with the tanks in the lab. I very rarely...
  83. dw1305

    Latest ph Profiles

    Hi all, I'm not, nor ever will be, a CO2 user, but I don't think you (or your fish) need to be concerned about the changes in pH from adding CO2. The same can't be said for a lot of snails, where pH below pH 7 will cause <"shell attrition">, and some fish (lake <"Tanganyika cichlids">?) may be...
  84. dw1305

    Drop checker solution

    Hi all, It is easy to do, you just need sodium bicarbonate (NaHCO3) and bromothymol blue pH indicator. Because baking soda is really cheap you could make up 5 litres of solution, it is much easier to work with <"larger weights and volumes"> and then just add <"bromothymol blue"> to make up 500...
  85. dw1305

    Why Advise A 1pH Drop?

    Hi all, A search on UKAPS for <"hypercapnia"> and <"nephrocalcinosis">, should yield some more references. cheers Darrel
  86. dw1305

    Why Advise A 1pH Drop?

    Hi all, We have some <"older threads"> where Tom Barr @plantbrain <"talked about this">. I'm not a CO2 user, but the <"sub-lethal effects of elevated CO2"> would worry me if I was. You can use 2dKH solution in your drop checker to give you a light green response at 15ppm CO2. cheers Darrel
  87. dw1305

    Why Advise A 1pH Drop?

    Hi all, Not sure what happened there, that should have been "3 ppm". I'm not sure about this either, bromothymol blue is a narrow range pH indicator, but I don't know at what CO2 level it reverts to blue (in a 4dKH solution). According to the chart it is definitely blue at 5 ppm CO2 (pH 7.4)...
  88. dw1305

    Why Advise A 1pH Drop?

    Hi all, I don't think we ever found out where the "" came from. The theoretical value is <"~about 0.5 ppm">, which depends upon the 400 ppm of CO2 in the atmosphere and Henry's Law. That is where the drop checker comes in, as long as it returns to blue you can be fairly sure you are out-gassing...
  89. dw1305

    Why Advise A 1pH Drop?

    Hi all, I don't claim any proper understanding of this, but I think that is the point. The dKH doesn't remain constant because you have the pH ~ CO2 ~ carbonate equilibrium which changes as you add CO2. Once you have more than ~4dKH of carbonate buffering the pH will always equilibrate to pH...
  90. dw1305

    Why Advise A 1pH Drop?

    Hi all, We think the reason is that a one unit of pH drop will always be equivalent to about 30ppm of CO2, what ever the dKH is. With the usual disclaimer that I'm not, or are ever likely, to be a CO2 user, there is an fairly complete explanation in <"Question about ...">. Have a look at...
  91. dw1305

    PH profile

    Hi all, All you do is measure the tank pH, at regular intervals, from before you switch the CO2 on (when the drop checker is blue) <"through-out the period when the CO2 is on"> until the drop checker has returned to blue (after lights out). Have a look at @foxfish's comments in <"CO2 equipment...
  92. dw1305

    JBL ProFlora U502 with Inline Diffuser

    Hi all, Perfect. There are number of variables, so bubble rate isn't really very useful. cheers Darrel
  93. dw1305

    JBL ProFlora U502 with Inline Diffuser

    Hi all, You really need a drop checker and/or a pH profile. Have a look at <"Clay Pellets and CO2....."> If you just use bubble rate you run the real risk of asphyxiating your fish (if you end with too much CO2). I'm not a CO2 user, but others <"will be able to advise you">. cheers Darrel
  94. dw1305

    Time for.co2

    Hi all, Same thought for me. cheers Darrel
  95. dw1305

    Not a good write up for liquid carbon

    Hi all, He used to post on <"the Krib"> as well. Back to <"Calvin-Benson">. It is a shame, but I'm sure you are right, and we are unlikely to ever find out how any of these products actually function. cheers Darrel
  96. dw1305

    Not a good write up for liquid carbon

    Hi all, The Seachem marketing blurb is absolutely world class in terms of <"implying something">, but without ever saying anything that could be disproved in a court of law. It used to really annoy me, but now I quite enjoy reading them. cheers Darrel
  97. dw1305

    How much carbon in natural waterways?

    Hi all, Beavers? That would be the total phosphate, it is largely getting into water courses bound to soil particles. In my experience thi is particularly from Maize and Potato fields, because these tend to be in river valleys and have a long period where they don't have any vegetation cover...
  98. dw1305

    How much carbon in natural waterways?

    Hi all, It would definitely help if lakes and rivers had more structure (meanders and sunken trees etc) to provide cover for larger fish, and healthy populations of fish eating birds, otters etc. <"Re-introducing the Beaver"> (Castor fiber) would be a start, but none of these things are very...
  99. dw1305

    Liquid Bio Carbon

    Hi all, It isn't a product I would ever use, as either an algicide or carbon source. There is this thread <"How much CO2 does .....">. I'm not sure there are any scientific references for glutaraldehyde as an organic carbon supplement, but it is really difficult to search for on Google Scholar...
  100. dw1305

    Co2 injection in large tanks

    Hi all, I think it was Clive who told us originally, but you are right the amount of Dissolved Inorganic Carbon (TIC or DIC) is set by the concentration of CO2 in the atmosphere. When you add pressurised CO2 you have added H2CO3 and the pH falls, how far it falls is dependent on the CO3...
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