I think you just don¡¦t understand the relationship between pH and carbonic acid. There are many people that do not pertain to your "high tech" method for growing plants. There are many angles you can look at this and as with most data we find that data that supports our theories. "O2 > Level is entirely > Determined by external factors" External factors certainly play a point in this but to say that CO2 levels are "entirely" determined by external factors is just not a scientifically sound principal. ¡§that whole > triangular relationship between pH, KH and CO2 > breaks down at low KH, > because it is no longer a buffer solution. The pH > can fluctuate wildly > with even the slightest change in CO2 level (or > frankly, with any other ?« acid or base added to the system).¡¨ This whole buffer solution system is so misunderstood by many hobbyists in my opinion. Why will pH fluctuate, just because we have a KH of 0 do we assume the pH will simply bounce all over the place? The relationship of KH to pH, is not if we have 0 KH then we no longer have a ¡§buffer¡¨ this is a incorrect way of looking at this. A high KH will help maintain a Higher pH and vice versa a low KH (for example a 0 KH) will help maintain a lower pH. Yes if we add chemicals this is going to fluctuate of course. Especially if we add CO2 injection. However I am not advocating adding CO2 to a system with sufficient CO2 present as can be found in a system with a low KH and pH. All my tanks have a 0 KH and I don¡¦t have any so-called pH bounce or crash. I just change my water regularly and dispose of the organic compounds that would begin to leech acids over time. Most importantly the plants themselves will do a great job of maintaining you pH. A healthy tank with good plant growth will have a higher pH. Why? Because the plants are using up the CO2 and thus there is less available to make carbonic acid. I have several friends with Chemistry and biology degrees that work in the field of environmental engineering here in Orlando. They are old college buddies. We talk and discuss these relationships with lakes and our aquariums. I have studied this in the real world not in books. I think sometimes we read too many books and just and take a ¡§respected¡¨ authors¡¨ word as fact. To me my data is where I learn from. My pH meter, my conductivity meter. Applying principals I have learned in books and testing them in the field. All these relationships I speak of I have seen both in my aquariums and in lakes and rivers. I have a deeper understanding of them through my own research and testing of such theories. You are correct ¡§lush¡¨ growth is subjective. I will say I see no need for CO2 injection in my systems and I am very happy with my plant growth. I have plenty of light and fertilization and there are no limiting factors affecting my plant growth. Saying that you have to have CO2 injection for proper plant growth is incorrect. I have yet to see any natural bodies of water with CO2 injection. ?º "Anyway, this is using up more time than I have. For > more info, I suggest > reading the Krib or archives of the Aquatic Plants > Digest." I think a bit nippy and a bit uncalled for. Comes across the wrong way and could easily lead to a flame war. I think we need to respect the opinion of others and treat each other with the same respect we would like to receive. I think if you don¡¦t have the time to engage in such discussions then simply don¡¦t. I don¡¦t think we agree on this subject and guess what that is ok. Perhaps the Apisto folks would rather hear about Apistos anyway. Keep well David Sanchez --- Erik Olson <email@example.com> wrote: > On Mon, 28 Jan 2002, David Sanchez wrote: > > > My point is that there is a correlation between > KH, > > pH,and CO2. This what I said > > > > David said > > "hy are yoiu using a CO2 system if you have water > > > with > > > > oKH to begin with Colin? The lower the KH the > > > higer > > > > the CO2 level." > > > > > > My > > point is that if you have a low KH and low pH > there is > > no need for CO2 injection because using these > factors > > we are able to determine the level of CO2 in a > system > > of water. The fact is that by measuring the level > of > > both pH and KH you will have the CO2 level in your > > system. From this premise we can determine why we > do > > or do not need a CO2 system in our aquaruims. > > And my point was that this statement is UNTRUE. CO2 > level is entirely > determined by external factors, such as atmospheric > concentration, > injection, and respiration. So to claim that Colin's > tank has enough CO2 > because his KH is very low is untrue. > > Now, if you are using the "charts" to determine the > CO2 concentration > based on the pH and KH readings, you should > understand that whole > triangular relationship between pH, KH and CO2 > breaks down at low KH, > because it is no longer a buffer solution. The pH > can fluctuate wildly > with even the slightest change in CO2 level (or > frankly, with any other > acid or base added to the system). There are some > nice analyses by Roger > Miller and others on the APD on that same URL I gave > you for the chart > that shows how little you can rely on the charts, > especially at the > extremes. > > > > I have not had a CO2 systemn in any of my > aquaruims yet my tanks have > > lush plant growth. I do need a CO2 system because > I already have > > enough CO2 in my system. DO natural bodies of > water have CO2 > > injection? no they do not. My point here and what > awe are discussing > > is the need or lack there of of a CO2 injection > system. Just saying > > you have to have a CO2 system to have good plant > growth is not > > corrrect and is based on a lack of understanding > the relationship of > > all the given data. > > "Good" or "Lush" Plant growth is a very touchy and > subjective subject > amongst plant enthusiasts. In our fishroom, Kathy > and I have some 25 > tanks. Most of them have a single tube of > fluorescent light over them > (maybe 1.5 watts per gallon), use aeration, and grow > plants like Anubias > nana, Water sprite, and Java Fern quite nicely. In > three of our tanks, we > have double that light, use power filters, and > bubble CO2 into the > filters. These tanks grow more "difficult" plants > like tenellus and Sag. > One tank has maybe 4 watts per gallon and injects > CO2 through a reactor, > and I fertilize with Tropica Mastergrow. In this > tank, we grow our most > "complex" plants like Rotala macrandara and > Glossostigma elatinoides. > All these tanks could qualify as "lush", but by > different standards. > > Anyway, this is using up more time than I have. For > more info, I suggest > reading the Krib or archives of the Aquatic Plants > Digest. > > - Erik > > > -- > Erik Olson > erik at thekrib dot com > > > ------------------------------------------------------------------------- > This is the apistogramma mailing list, > firstname.lastname@example.org. > For instructions on how to subscribe or unsubscribe > or get help, > email email@example.com. __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com ------------------------------------------------------------------------- This is the apistogramma mailing list, firstname.lastname@example.org. 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