Cichlidiot wrote in message
...
Mark Stone wrote:

Nitrite is the product of the breakdown of Ammonia, so the nitrite
spike following the ammonia spike is normal. Since your RDs are
already beyone juvi stage, there should be no danger to them as the
tank goes through this process: but as the ammonia and the
subsequently the nitrite spike, do some partials. In my experience,
establishing a tank takes about five weeks, dependent upon many
variables.

Umm, I'd have to disagree about them not being in danger. Nitrite
poisoning can occur at any age, even though juvenials are more suceptible
to it. The symptoms of lethargy would be consistent with nitrite poisoning
(aka brown blood syndrome or technically, methemoglobinemia). What happens
is the hemoglobin in the blood binds with nitrite (instead of oxygen)
creating methemoglobin, which cannot transport oxygen. Too much
methemoglobin and the fish literally suffocates because it cannot
transport enough oxygen in its blood. The first symptoms are lethargy, at
which point you usually can save most of the fish with some intervention.
If they reach the stage of gasping, they're usually goners unless you can
almost completely remove the nitrite through a 70%+ water change or
removal to a nitrite free tank (which in and of itself could stress the
fish into death, but it worth a shot rather than let them suffocate). Fish
respond individually to treatment of nitrite poisoning as well, depending
on their overall health. So, depending on how far it has progressed, you
may lose a few or save them all, but in any case, I'd do the following
immediately.

There are two main ways to deal with nitrite poisoing, massive water
changes and salt. The water changes have an obvious effect, diluting the
amount of nitrite in the water. If your tap water is close to the tank
water's parameters, change at least 25% if not 50% every day until you
bring the nitrites below 1ppm (I surely hope you have a water changer like
a Python or a really strong back for bucket lugging, heh). The chloride
ions in salt can prevent the uptake of nitrite in the gills, which
prevents it from entering the bloodstream and creating methemoglobin. With
a 220 gallon tank, I'd recommend adding rock salt (rock salt is pure
sodium chloride and easily found at a grocery store for much cheaper than
salt at the fish store. NOTE: You don't want table salt as it contains
additives) at the rate of about a tablespoon to 50 gallons to help ease
the symptoms of nitrite poisoning along with the water changes. This means
add about 5 tablespoons now and then if you change 100 gallons of water,
add another 2 tablespoons. Many recommend dissolving the salt in a cup of
water before adding it, which I would do with curious cichlids (with
smaller fish who couldn't eat the salt, I usually just evenly spread the
salt around the tank, but the one time I tried that with my cichlids, they
kept mouthing the pieces).


Sounds like good advice to me.

I know nothing about Red Devils, but...

After a couple of days of 50% water changes, the fish will appear to be good
and healthy. You may be tempted to cut back on the water changes.

However, they won't have fully recovered from their ordeal. The Nitrites
will build up again and the fish will not give you as much warning as
before. The first thing you notice will be dead fish.

You must keep up the water changes until the tank has cycled completely.
And then you should still do twice weekly changes for a while.

Good luck.

Jim