Harro
-----Urspr|ngliche Nachricht-----
Von: r_m_l at yahoogroups.com [r_m_l at yahoogroups.com] Im Auftrag von
Julie Zeppieri
Gesendet: Freitag, 25. November 2005 17:43
An: r_m_l at yahoogroups.com
Betreff: RE: AW: [RML] Re: pH and fish physiology
So, Harro, then how is it that the gills are harmed when fish are put
into
water with a lower pH? And why is it that this effect is less when fish
are
taken quickly to a higher pH instead? What is the actual physiological
process that occurs to do this?
I admit, this was for a friend, but now I am curious to know this as
well.
Julie <'><
>From: "Harro Hieronimus" <harro.hieronimus at t-online.de>
>Reply-To: r_m_l at yahoogroups.com
>To: <r_m_l at yahoogroups.com>
>Subject: AW: [RML] Re: pH and fish physiology
>Date: Fri, 25 Nov 2005 12:34:22 +0100
>
>I dont think so as the TDS does not mean a certain salt content, its
>just a sum which says nothing (or nearly nothing) about the composition
>of the water. Additionally, the osmotic shock does only occur when the
>salt (NaCl) content is very different. With the pH in the range of 6.5
>to 7.5 you will have no problems. But its the acidity and the alcality
>that harms the gills and the mucous. You may change the pH without
>changing the TDS and that causes problems, most of all (as mentioned
>before) when you place a fish from high to low pH with less problems
>reverse.
>
>
>
>Regards Harro
>
>
>
>
>
>-----Urspr|ngliche Nachricht-----
>Von: r_m_l at yahoogroups.com [r_m_l at yahoogroups.com] Im Auftrag
von
>Eileen Kortright
>Gesendet: Freitag, 25. November 2005 12:11
>An: r_m_l at yahoogroups.com
>Betreff: [RML] Re: pH and fish physiology
>
>
>
>--- In r_m_l at yahoogroups.com, "Julie Zeppieri" <bowluvr at h...> wrote:
> > A friend asked me why it is -- metabolically/physiologically
>speaking --
> > that it is more dangerous to
> > fish to experience a sudden drop in pH than for them to experience
>a sudden
> > rise in pH.
>
>Here is an excerpt of a post written on the pH "myth" by
>daveedka on AquariaCentral.com. Dave is most excellent at explaining
>stuff so that even a noob like me can understand :)Perhaps someone
>can take this further and form a theory?
>
>
>. . ."I do own Ph test kits, and do use them, but seldom worry about
>what my PH actually is or how much different tank and tap Ph really
>are. The fish react to the level of dissolved solids, not the actual
>ph of the water. PH "shock" as it is commonly called in the hobby is
>actually Osmotic shock caused by taking a fish from water with one
>TDS (total dissolved solids) level, and putting them in water with a
>far different level. This interferes with osmo-regulation and harms
>the fish (or in mild cases stresses the fish) fish can and will
>adjust to changes, but it takes some time. My tanks range from 6.6-
>7.2 Ph with co2 injection, my solids levels and Carbonate levels are
>constant and consistant with my change water. the fish don't know
>the difference in the ph.
>
>All of this is of course within the ranges of normal Ph's. Extreme
>high's and lows will still do harm, but seldom does this discussion
>ever contain the extremes. I have seen tanks with OTS that regularly
>tested at ph of 5 and the fish survived. and likewise I have seen
>fish kept in tanks with ph of 8.8 with no problems.
>
>That being said, the Ph myth is huge and largely mis-understood.
>It comes from the fact that what we as humans view as hard water is
>far different than hard water in the sense that fish care about.
>Human hard water is water that is hard to get soap suds in, for fish
>it is water that is high in TDS (total dissolved solids). A person
>can take RO water and adjust it to a Ph of 8.2 and have less
>dissolved solids than high calcium water would have at a ph of 7.0.
>The Ph correllation is extremely general and far too much emphasis
>is put on it. Here in Columbus Ohio we have tap water that is
>pathetically devoid of everything. Our water comes from the pipe at
>close to 7.0 ph most of the year. it changes to 7.6-7.8 after
>sitting out for a while. Now the crux of the matter is: there isn't
>enough calcium, magnesium, trace minerals etc. in that water to grow
>plants, snails, or shrimp. By all rights our tap water at 7.8 ph is
>nearly perfect for ultra soft water fish like tetra's and discus.
>Mollies and swordtails will not breed in our tap water because it is
>so soft. on the flip side I can take that same water and make it
>rock hord with calcium and magnesium and never alter the ph one
>iota. Then I have water ideal for rift lake fish, mollies, snails,
>shrimp etc. and the ph is still exactly 7.8.
>
>A water softener exchanges calcium and magnesium ions for sodium
>ions at close to a 2 to 1 ratio. In other words the water going in
>is high GH, we double (general term not mathmatically accurate) the
>dissolved solids, and it comes out reading a lower GH. Discus would
>rather have the water before it was "softened"
>
>Now thus far we have talked about calcium and magnesium, and of
>course carbonate. Our GH test kit picks up an Ca and Mg, but does
>not read other items in the water. Our Kh test kit picks up on
>Carbonate, but does not read other factors. So we could feasably
>have high iron, high sodium, high sulfur etc etc. And our test kits
>read ultra soft water. Dump a discus in a high sodium high sulfer
>tank sometime (please don't do that for real) and you'll find out ph
>Kh and GH readings mean next to nothing in the total picture.
>
>Likewise we could take ro water add enoguh calcium and magnesium, to
>get a gh of 18-19 dGH and just enough carbonate to get a KH of 3dKH
>and we would have a ph of 7.8 or 8.0, Medium hardness reading,
>medium to low Kh and high Ph. With nothing else in the water, our
>fish would still see it as very soft water.
>
>There are so many variables in the PH discussion, and so many right
>and wrong ways to influence Ph that in the end it proves to be a
>somewhat useless number. It is good for viewing changes, it is
>excellent for calculating co2 levels (if carbonate is the buffer and
>not phosphate) but aside from that it is limited in what it will
>actually tell us. Additionally because of the emphasis put on PH
>readings by so many people in the hobby, it causes a lot of
>confusion, a lot of headaches, and in many cases it kills a lot of
>fish.
>
>In the wild, the water works under different rules, we have large
>volumes of water with small numbers of fish. A KH of 0 in the wild
>is not a big issue because there is enough water to dillute the
>effects of biological acidification a KH of 0 in our tanks is a
>recipe for dissaster. Many People constantly work for a PH of 7.0,
>when in fact they are setting themselves up for an unstable tank
>environment when they do that. Our tap water at 2-3 dKH is Ph of 7.6
>at atmospheric co2 levels. This tells me that unless I'm injecting
>co2 I never ever want a tank with a PH below 7.6 PH.
>When we use products like peat the tannic acid depletes the
>carbonate, the calcium and the magnesium (at least that is my
>understanding at this point) this is a good and useful thing to know
>if we have extremely hard water and we want to raise Discus fish. It
>is not a good thing if we don't understand the whole picture and we
>over soften our water and crash the tank.
>
>Trying to get the entire aquarium hobby to see this is difficult at
>best."
>
>Dunno if that helps you at all,
>
>Eileen
>(Roan Art)
>
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