Growth Inhibiting Substance/Hormone

[Sakura]

I've always heard about this on goldfish sites, and assumed that it was true because it sounds plausible. Basically it's said that goldfish excrete some type of hormone that inhibits growth at high concentrations. It's always used as a reason for doing frequent, large water changes. I'm not questioning the worth of frequent water changes... I believe that to be necessary with goldfish! I just want to know if there's any truth to this growth inhibiting hormone thing. Anybody know? I just don't want to keep telling it to people if it's not actually true. I've tried to look up scholarly articles about the subject, but didn't have much luck finding anything.

[Ranchu Rancher]

Yes they do exsist. http://www.aquariumpros.com/forums/archive/index.php/t-1457.html Go to this site and there is info on it. So continue telling people to change there water. :exact:


Gregg

[fantail1]

The link provides statements, but no specific evidence to support a theory. The references are to materials that when I google them I get other uses of the same references but not the original materials and all the references go back to the 1970s and 1980s. Is there anything more recent that this? Does anyone have the underlying research?

All in all this link doesn't provide evidence. It could just be excess nitrates act as an inhibitor.

That doesn't mean water changes aren't necessary (unless you have a way to remove nitrates....) it just means, in my opinion, there may or may not be GIH.

[Ichthius]

It could just be excess nitrates act as an inhibitor.

And all sorts of other metabolites. Biofilters digest hormones too.

Modern day high intensity low discharge reticulating aquaculture wouldn't be possible if it was an issue.

There are lots o thugs that can accumulate in water. Changing the water is the best way to remove them and nitrates are easy to test for. I you have a lot of nitrates you have a lot of what ever else is in there.

[fantail1]

I was simply using Nitrates as an example - sorry if I wasn't clear. The point is that there is nothing in the link that shows more than a theory that the Goldfish are producing the problem. Unless there is proper scientific evidence, it is a guess, the same as nitrates...

By the way, if Godfish do produce GIH, how come they outgrow aquariums?

[Ichthius]

And that my attempt to further your point. :)

And a bunch of wet hands iphone typos.

What youre not supposed to use an iPhone with wet hands? That wasn't in the owners manual!

[fantail1]

sorry David, that one is lost on me

David

[Sakura]

I said this already, but I'm not saying that I'm going to stop changing my water if the GIH thing isn't true. I still believe in doing large and frequent water changes no matter what...

I wanted to know about the GIH thing just out of curiosity, because like I said, I don't want to be giving out false info to other people.