Hi Leon,
Quote:
Originally Posted by le0n
My first thoughts are it won't be a problem with Hydroponics however you never know. So is Zinc or using galvernised fitting in the system a problem?
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Trout fingerlings are indeed very sensitive and just some ppm of te wrong stuff in the water might indeed kill them. Plants, even seedlings aren't that sensitive and are able to metabolize with ease what actually may kill trout fingerlings straight away.
If I am not mistaken those fittings are used for house water systems, aren't they? Well, if so - you would kill your plants when hosing your garden and soil... if there was that much zinc getting "dissolved"
Just be careful with any kind of acids (PH down), they could actually dissolve some more zinc as would be of any good.
Still, as I live in Thailand I am well aware of the problem that you never know what they actually use in their alloys and coatings. Their might be some contaminants in heavy metals or stuff. If I was in your case, I would try to find some PVC or any synthetic fittings for future projects, it's safer.
About the "danger" of high temps in root zone when ebbing due to "hot air"?
I don't agree with GPS at all. It doesn't work like that. Firstly the air isn't literary sucked in and it obviously cools down in wet media as well. And then there is the temperature of the media, which has a puffer. Secondly there is a difference between ideal
nutrient temperatures and the root zone temperatures in media. If you have buckets like yours (I also have similar systems running) the temperature may raise anyway as the buckets are exposed to direct sunlight and at ambient outside temperatures at all time. Although the humidity in the media will cool them somewhat down (which is good). Yes, you need to care about the temperature in the buckets (root zone), but you will not be able to keep it between 68 and 72 anyway- that's simply impossible. In wet or dry soil (which is pretty similar to a bucket filled with media) there are also huge temperature fluctuations that exceed 70 or 80 by quite a bit. Roots can cope with- and adopt to that in the tropics.
In brief: I do not think that there is a problem of the sort with Ebb&Flood.