Posted by patrick73 on February 07, 2003 at 10:48:05:
In Reply to: Wattley\'s theory about growth inhibiting hormones? posted by mutlu on January 21, 2003 at 14:02:57:
:Hi,
:I know that Jack Wattley has a theory about Discus releasing some organic substances that inhibit growth. I am looking for scientific evidence about this phenomenon. Does anybody know about weblinks, journal articles, books, that discuss this theory.
:Thank you.
Hello. Let me first start off by stating I'm not an expert, but I have kept discus successfully for two years now since I got into the hobby.
I like Mr. Wattley's column as it is informative. However, I've read alot of what one might say diplomatically is dissent on his suggestions or the validity of his information or theories. Without going further into it, I've read from other authorities on discus who have disagreed with certain assertions he has made. However, it seems most of the others concur with Jack at least on the basics.
It seems to me that the question of growth inhibiting hormones is more a hypothesis than a theory as this would imply it were tested scientifically. From the bit of research I did before posting and from what I read in the past, I get the impression that many don't really believe this.
The end result, however, is the same. The idea of growth inhibitors is given as a main reason for the water changes, but seems more likely that the growth inhibition is more due to nitrates accumulating in the water. Nitrates can be removed through water changes, or a fairly well planted tank can help in reduction of nitrates and apparently reduces the frequency of water changes (which should still be done however, even if the plants supplement to a degree and provide some lee-way). So, the end result is more frequent water changes leads to optimum growth, but probably not by removal of some mystery anti-growth hormone, rather more likely from removal of nitrates.
Once again, I'm not an expert--far from it. Just passing on what I've read. If anyone cares to add to or correct information in this post, please do so.
