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pH

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  1. PH & salt water fish blindness
    by laurence/cco.caltech.edu (Dustin Lee Laurence) (1 Aug 1993)
  2. [R] injecting CO2
    by hurley/robadome.com (Jim Hurley) (28 Jan 1994)

PH & salt water fish blindness

by laurence/cco.caltech.edu (Dustin Lee Laurence)
Date: 1 Aug 1993
Newsgroup: rec.aquaria

drising-at-halcyon.com (David Michael Rising) writes:

>Can anyone tell me if low ph (around 7.5 I'd guess since my kit won't
>measure that low) can frequently cause fish blindess or at least perhaps
>nearsightedness?

I can't tell you that, but I can tell you that 7.5 is dangerously low.
It would be much more surprising if you didn't have fish dying.

For reference, the ocean over a reef (where tropical marine fish come
from) usually ranges between 8.1 to 8.3, depending on time of day.

>Has anyone ever used Vitamin E to stimulate fish appetite?  If so, what
>methods are used?

This is just treating the symptoms, and is not likely to do much in
the long term.  Fix the pH problem.

>Also, can Arm & Hammer Baking Soda be used in salt tanks instead of
>buying those off the shelf ph buffers.  My ph seems to run consistenly
>low, esp. after water changes so I'm guessing my tap water ph is real
>low.  If A&H isn't the same as those marine ph buffers, what's a good
>brand to use?

You should definitely add some kind of buffer.  I also suggest very
strongly that you buy a kH test at the same time; you should not risk
fooling around with this water parameter without being able to check
what is happening.  The Seatest kit is inexpensive (it lasts a long
time for what you pay, compared to most other aquarium test kits) and
works very well.

You should know that when you start adding a buffer, things may get
worse before they get better.  Your fish are somewhat acclimated to
the low pH, as well as they can be, and when you add buffer the pH
will fluctuate before it stabilizes.  This can be very nasty to
invertebrates, and if your fish are already weakened (as they would
be in this case) I would speculate that it may hurt the fish too.
But they are not going to get better if you don't do anything, so you
have little alternative.  I only make this point so that if things
get rough for a week (could be two or three, given your starting
point), you won't give up on the buffer.  At the end of the process
you can get the pH stabilized quite well.

Baking soda can be used, but IMHO should not be (there are others who
feel differently.  Baking soda will either cause a rapid short term
drop o a rise in pH, I don't remember which.  Martin Moe's Marine
Aquarium Reference has a discussion of this very topic; if you insist
on rolling your own, you _should_ read this.

On commercial buffers, first the one I don't recommend.  Don't waste
your money on Thiel's kH buffer--the stuff is IMHO garbage.  Just say
no.  It is overpriced, or used to be, and in my experience it does
not stabilize the pH well at all.  Nasty experience for the
invertebrates, too.

Marine Buffer works well, and a container of it should last quite a
while.  My only complaint is that I can never get the stuff to
dissolve unless I literally grind the undissolved powder against the
bottom of my beaker; I actually keep a small 50ml beaker just for
this purpose, and it has never dissolved for me otherwise (yes, I
dissolve it in freshwater as the directions say, DDI lab water
actually).  I bought a large container of it that may last me forever,
so I put up with it.

I like Kent's buffer.  Among other things, it dissolves pretty quick
and completely.  Much more convenient.  I don't remember how it
compares pricewise.  If the Marine Buffer jar ever gives out, I will
probably replace it with the Kent SuperBuffer.  However, since I only
add buffer every few weeks, I put up with the trouble.

One last tip; when you mix up the buffer solution, don't add it all at
once.  Get a piece of airline tubing with a plastic valve on one end
and drip it in slowly.  If you can get the rate low enough, dripping
it in over several hours would be ideal.  The limit on this is that
there will be some clogging--though not nearly as much as if you were
adding limewater.  This slower process may lower any stress that your
boxfish may feel.  Also, if the fish does show signs of being stressed
by the initial buffer addition, consider a different schedule, such as
adding half as much twice as often.  And starting the dripline at night
just before you go to bed may help as well, since the pH will tend to
drop at night on its own.

Good luck,

Dustin


[R] injecting CO2

by hurley/robadome.com (Jim Hurley)
Date: 28 Jan 1994
Newsgroup: rec.aquaria

In article 9uL-at-ra.nrl.navy.mil, tse-at-ra.nrl.navy.mil (Anthony Tse) writes:
-->    I just ordered a CO2 injection system for my 60g reef to keep
-->the pH from poking holes in my ceiling.  The tank has no sump,
-->and it's full rock and corals, so fitting a CO2 reactor in there
-->would be rather difficult.  So, what's the best way to get CO2 into
-->my water?  One suggestion was to feed CO2 into the intake of a power
-->head.  

This is the easiest way, in my opinion.

-->Then I was warned that the CO2 won't have enough time to
-->dissolve.  

You'd be surprised. In a Magnum 220 that I use, a bubble or two per second
is easy to consume. I don't remember just how quickly I can drop the pH,
but it is really amazing how absorbtive CO2 is. In salt water perhaps there
may be some slowdown due to the higher KH, but I doubt it.

-->I thought maybe my skimmer, but there is so much air
-->blowing around I probably loose most of the CO2.  

Think about this though - if the CO2 leaves the water where will it go?
It's heavier than air, so a lot will remain in the skimmer, which will tend
to saturate the water again. I think you will reach an equilibrium rather
quickly.

-->Then someone
-->wants to sell me a reactor anyway.  I ask him what kind of flow
-->rate it needs, and he said any flow rate you like.  So what's
-->the difference between blowing water out of a power head into my tank
-->vs blowing water thru a pipe full of plastic balls then into my tank?

You wonder sometimes don't you? Personally, I don't believe that turbulence
stuff when you are injecting CO2. Sure if you are depending on the minute
amounts of atmospheric CO2 as food for your plants, then by all means take
care to reduce turbulence, but if you are injecting CO2, don't bother.

A while back I once tried this: I wanted to make a 30gallon water change in
my 100g tank. The 100g is regulated at pH 6.8, the tap water in the 30g
bucket is aged, warmed, and at pH 8.4. So I added a T-valve to my CO2 system
and squirted some CO2 bubbles into a powerhead running in the 30g bucket.
After about 30 seconds I thought I'd check to see how much further I needed
to go. Wow! pH was at 5.0! Now I had the reverse problem, get rid of that CO2.
So I put in all the pumps and powerheads I could, splashed and sprayed water
to get as much turbulence and agitation as possible. It took about half an
hour to get the pH from 5.5 up to 6.8.

-->
-->-Anthony

---
Jim Hurley       E-mail: hurley-at-robadome.com   GEnie: J.HURLEY1 
ROLM - A Siemens Company
PBX SW Development - Callbridge Applications     (408)-492-2228


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