Re: [RML] ionic strength, avoiding fish kills

Julie Zeppieri (bowluvr at
Sat, 03 Dec 2005 10:04:05 -0800

Thanks, Gary. :-)

The KH of the Rift Lake tanks is 13. That is what the buffer is designed
for. Never measure the GH, but my guess it is also moderate-to-high from a
read of the buffer's ingredients. In the Rift Lake tanks, ironically, I do
not use any crushed coral or shell, just the buffer. I only use crushed
coral/shell (and in small amounts) in my non-Rift tanks to keep the pH from
bottoming out -- even with discus and Apistos, as I have had the pH drop to
2.8!! The Apistos in the tank did fine, but I tested it due to the fact that
the clump of previously happy Java Moss had gone to brown mush. ;-) GH/KH
in my non-Rift tanks is in the low/soft range generally (tho not overly so)
unless I tweak it further. I rarely do this BTW, as soft is fine for my
needs for the most part. Even the guppies and rainbows don't mind soft so
long as pH is not low as well.

The main point to all my questions and such is that I am really not trying
to find out IF pH drops are dangerous (I know they are), but WHY they are.
My friend asked the physiolgy behind this, and I guess the ion thing by
itself just doesn't seem like the right answer. Perhaps a part of it, but
there are just things it does not address.

I guess my next move is to try and contact the "wet vet" we have here in
Oregon (U of O, Hatfeild Marine Science Center, and Oregon Coast Aquarium
affilated -- busy man!). Hopefully I will get a reply, or at least some
literature links. If I get a full explanation on this I will forward it to
the list. I was just hoping to do this "in house" since so many of you are
in the habit of knowing such details usually. :-)

Julie <'><

>From: Gary Lange <rainbowfish4u2 at>
>Reply-To: r_m_l at
>To: r_m_l at
>Subject: Re: [RML] ionic strength, avoiding fish kills
>Date: Thu, 1 Dec 2005 08:38:20 -0800 (PST)
>Ok, so reading and answering questions on coffee break is not the best
>idea. <some> of the stuff he said made sense, other items didn't. I agree
>that going from high pH to low pH, even with pretty much the same ionic
>strength could zap your fish. I'm usually taking fish from someone with
>well water (400 ppm GH, lots of KH and who knows how many other ions, pH ~
>7.8 or higher) and moving it to my 125 ppm GH, 3 degrees (~ 54 ppm) KH and
>fairly low in ions, pH ~ 7. So most of the time I'm dealing with both
>effects. Like you, I have gone from low to high (ions/hardness or pH) w/o
>any problems too, fairly quickly, w/o any problems.
> Have you ever measured the GH/KH of the water that you are keeping your
>Africans in? I would bet that the aragonite or crushed shell/coral has
>raised your GH & KH a fair amount and it's probably higher than you think.
>Bottom line, take home message though is don't go from high to low,
>quickly, do it slowly. Take a few hours or even overnight for really big
>differences. Dripping from the tank into the bucket with the new fish is
>the best way to accomplish this w/o too much hassle. Just keep a lid on
>those bows as they really get crazy in a bucket!
> gary lange
>Julie Zeppieri <bowluvr at> wrote:
> So, then, Gary, does this mean that you agree with that forum-guy's
>explanation of the physiological "whys" in which taking a fish from high pH
>to low will likely kill it, but taking it from low to high will likely not
>hurt it?? I don't really see how that works, myself.
>Seems to me this does not take into account that the ionic content of the
>water may be close to the same from the "higher" pH to the "lower" one --
>such as when one goes from say a 7.1 down to 5.4. I can get a higher pH
>water here in Portland w/out greatly altering either KH or GH, and I don't
>ever use much more than just some crushed shell or aragonite to keep pH
>tanking (outside of Rift Lake tanks, at least). Don't use much NaCl either
>unless a problem (eg: Velvet) calls for it. Granted, I don't have a way to
>test ionic content, but my tests do show that my water is still considered
>"soft" even at pHs above 7. And yet in the above scenario, I *can* kill a
>fish by just dumping it into a 5.4 tank from out of a 7.1 tank, even a
>species which can theoretically handle the 5.4 if acclimated slowly, and
>despite the fact that it doesn't seem to me that the ionic content would be
>that different.
>However, when I "shoot the elevator to the top floor" by dumping Rift Lake
>buffer into a tank that was previously at about 7.4-ish and relatively
>sending it up to KH 13 and pH 8.3 (and goodness knows what GH or ionic
>content), and the fish don't even seem to notice, well, I must say I am
>stumped by this "ionic is the cause" answer. If this IS the case, can you
>explain it to me so I get it? 'Cause I don't.
>Mebbee I is just thick inna head or sumpin' -- dunno. ;-)