Permanent Hyposalinity For A Marine Tank? 7/29/04
I was wondering
if it would be okay to house marine fish without any inverts in 1.008 to
1.012 salinity for good? I've heard that low salinity is very easy on
these fish and reduces stress significantly and kills off marine
diseases used to 1.026 salinity (normal sea water).
<Well, there are
a lot of opinions out there on this subject. Many wholesalers and
transhippers may keep fishes in lower specific gravities in order to
help lower the possibility of parasitic diseases. However, in the long
term, such low specific gravities may not be safe. I've read of studies
that have demonstrated that fishes have suffered damage to their
internal organs as a result of long-term exposure to an unnaturally low
specific gravity. If it were me, I'd stick to 1.022-1.025 (I like 1.025)
and be done with it! Fishes have evolved to live in these specific
gravities over the eons, and it works just fine. Why change things now!
Regards, Scott F>
SG
HI BOB-
Quick one on SG. What is
the SG of seawater on the reef (excluding Red Sea) someone says it has
risen to 1026 is this accurate? After purchasing the deep six I realized
that my SG was 1016 I have raised it to 1020 over 3 days and would like
to maintain it at around 1022-1023 how does that sound.
Thanks
Tom
>>
Hmm, no, still closer to 1.025 (temp. adjusted) most everywhere
around the world.
For reef systems, closer to seawater is better,
though spg's that are lower are tolerated by most types of livestock...
and there are some upsides to lower salinity... greater gas solubility,
cheaper water changes, lowered disease pathogenicity... 1.022-1.023 will
very likely be fine.
Bob Fenner
Issues For Discussion
Dear Robert,
<Howdy>
Hello there, it's me again!!! I have a few
questions to ask you, so please bear with me.
<Okay>
Michael and I
are at odds as to what the comfortable salinity should be regarding my
reef tank. He thinks that I should bring it down all the way to
1.017-1.019. The SCMAS group convinced me to bring the salinity up to
1.024 and up. Will you kindly help settle this question?!? Do I have it
up too high and SCMAS is wrong or is Michael's assessment too low?!?
Whatever you say, I shall adjust accordingly. Every time he comes to
clean my fish tanks, he drastically brings it down by adding too much
fresh water and brings the salinity down somewhere between 1.019-1.021
which kills a fish or invertebrate (or so I think). What to do?!?
<By
and large almost all captive marine systems should be kept near seawater
spg... 1.025 or so... There are many valid reasons for keeping spg
artificially low for periods of time... to save money on salt mix,
reduce parasite pathogenicity, allow for greater oxygen solubility...
But permanently leaving spg low has proven to be trouble... especially
for non-fish livestock as you mention. I would elevate, leave yours in
the 1.024, 1.025 range. Bob Fenner>
Sincerely yours,
Aleida Ann
Graichen
Low Salinity Stress?
Hello Mr. Fenner,
<Anthony Calfo here...fellow Pittsburgher, and happy Steeler fan
today!!!>
I am new to the hobby and have about 6 months of experience
in saltwater and my 55 gallon tank is also approximately 6 months old.
I have read the WetWebMedia boards in search of something related to
this, but I could not find anything that I thought could help me.
I
had a problem a month and a half ago with a Yellow Tang who developed,
or was infected with parasites when I got him. I gave him a freshwater
dip and quarantined him for approximately 3 weeks and he seemed to be
doing good in the qt tank. One morning I woke up and turned on the light
and he was dead. Anyhow, the store I bought him from had me do all the
tests on my main tank where he originally was, and all the readings were
ok. They said to drop the salinity 2 pts per day until I reached 1.10
s.g..
<Severe. Only acceptable in systems without invertebrates/live
rock and dubiously extreme. Just because some fish are strong enough to
survive it doesn't make it right. This methodology has sprouted from an
anecdotal article which included the support of a the old Pittsburgh
AquaZoo curator who does consult a local store. Very controversial.>
They also said to hold it there for a month to make sure that if there
were parasites in the tank, they would not survive.
< conditionally,
but not guaranteed>
Anyways, I did that and the fish looked great,
but the live rock looked like it was dying and all of the worms were
gone.
<not a surprise...obviously and visibly damaging to everything
but the fish>
At the end of the 1 month period, I started on
Wednesday slowly increasing the salinity by 2 pts per day. Everything
looked ok except now my Coral Beauty seems to be refusing to eat, but my
False Percula Clown is still chowing like a pig. The Coral Beauty will
not eat flake, freeze dried brine, Pygmy angel frozen food, of Sea
Veggies. When the clown starts to feed he swims around with him but will
not eat anything. I do not know if my rock is dead or dying and it is
causing ammonia to rise and that is affecting the Coral Beauty or what.
<surely damaged your biological filter...to what degree remains to be
seen>
I am also confused on why my levels are what they are. Could
you please try to help me out and tell what I should do.
<at this
point patience, resumption of normal routine and water changes>
Some
of the live rock has turned white during the drop in salinity. I thought
that the algae dying on the rock could also have led to the Coral Beauty
to stop feeding, because he grazed on it a good bit.
<a small
stress... the salinity was principal and more severe>
I don't know if
I should pull the rock, or it will come back on its own as the local
fish store says.
I would sincerely appreciate your professional
opinion on this matter.
Thank You, Jim. Pittsburgh, Pa
<it will
come back on its own. After the water chemistry is assuredly stable, add
some fresh live rock to inoculate the damaged rock and all will be OK in
time. Best Regards, Anthony Calfo>
Blue Damsels salt levels
I currently have a 29 gal. Brackish tank, I have been told that blue
damsels can live with a salt level of 1.017 my tank is currently 1.018
with 2 archers an Orange Chromide and some bumble bee gobies. I wanted
to add a few damsels but am kind of afraid to add fish that I thought
needed 1.020 at least. Can they tolerate brackish water? Thanks
<They
can tolerate the lower salinity but are much better off being kept at
true marine levels. There are a few species of Damsels that are from
fresh or brackish areas, you might want to check into these. Take a look
at
http://home.rochester.rr.com/akom/FAQ7.htm for a list of the
freshwater ones and do some research for the brackish varieties. Ronni>
Salinity and health - 12/16/03
Hi, As I've been reading on in
various books, articles, ETC. I've read that the ocean has a salinity of
close to 35 ppm (sp. gr. 1.026) however the LFS (and any hydrometers
I've seen) suggest that 29 ppm (1.021) is perfectly fine. <Some even
state 1.018-1.019. Interferes with pathogenic abilities to thrive and
survive. I don't recommend this though except in quarantine. I
personally keep salinity at 1.025 in my main tanks> This got me really
confused, as I would love to see these animals thriving in the best
possible conditions for them, should I begin raising my salinity or is
29ppm good? <How are the animals doing?? If it isn't broken then it
doesn't need fixing??> I have a fairly lightly stocked 125 gallon A
small school of Chromis, Firefish goby, cinnamon clown, yellow tang,
six-line wrasse, sebae anemone, colt coral a few cleaner shrimp, and an
emerald crab. Any advice would be most appreciated. <I would work
towards 1.025 if there are problems or if it will ease your conscience
but otherwise use your inhabitants as your barometer for change. If it
ain't broke then don't fix it.
~Paul>
-JIM
