Plant ID and Do fish respond to GH or KH?
Subject: Plant identification
> Plant 2.
> Purchased as Aponogeton natans.
> Based on pictures I have of A. natans this plant looks correct a
> description given. However what I presumed to be a flower spike
> developed two young plants on it, and is still growing. I may be
> it is my understanding that A. natans does not reproduce in this
> this A. natans?
I had this happen once too. I can only assume that this plant is
a hybrid between A. natans and A. undulatus. A. undulatus
produces plantlets on its flower stalks similar to an Echinodorus.
Natans has been crossed with a lot of other Aponos because it is
so vigorous. If the hybridizer can fix the leaf characteristics
of the the other species (avoiding natan's floating leaves) and
still maintain the ease of culture found in natans, they end up
with a better aquarium plant.
Unfortunately, with this particular cross, what has been achieved
seems no more than a curiousity. I found that it produced almost
entirely floating leaves on very long stems. I completely covered
the surface of my 70G tank, and produced _huge_ numbers of
plantlets which added their floating leaves to the rats nest on
the surface. I ended up propagating them just long enough to get
my HAP points, then passing them on to some one else. They had
little decorative value.
Subject: Do fish respond to GH or KH?
> Karen writes:
> > ... almost any "community"
> > type fish can tolerate a pH of 8 if you don't intend to breed
> > them.
> OK, I intend to breed some! :)
> I'm trying to breed South American dwarf cichlids in my big plan
> Was just visiting cichlid guy extrordinaire Dave Soares, who sai
> basically that the species' ability to breed corresponds to the
> hardness, because the harder it is, the tougher the eggs are (an
> easy for sperm to penetrate them).
Well, I'm not sure that I would count S.A. dwarf cichlids as
typical community fish, but what he said is true. (or at least
there is definitely a strong correlation between water hardness
and lack of fertility... I'm not sure that the scientists are sure
what the exact mechanism is)
> Question: If I inject CO2 into hard water, will this effectively
> all the carbonates into carbonic acid, thus being equivalent to
> soft water? i.e., is pH REALLY the indicator I should be keying
No. That's my point exactly. Lowering the pH when you have hard
water is not going to allow you to breed sensitive soft water fish
either. For that, you must produce soft water. This can be done
by using appropriate amounts of DI or RO water, or by using the
old fashioned, but tried and true method of filtering the water
through peat _before_ it is used in the tank.
The problem with the peat method in our (planted tank) application
is that its use interferes with testing for CO2 levels. Your pH
will be lower than it would be with just CO2 injection because
you've added a different type of acid. (humic acids) So the CO2
charts are no longer valid. So you can _think_ you have a lot
more CO2 available for the plants than you actually have. I don't
believe CO2 test kits will work correctly either. The other
problem with peat is that it darkens the water. This _may_ be a
problem as far as lighting the tank is concerned.
That all said, short of RO or DI, I'd definitely consider peat the
next best option if I wanted to breed soft water fish. It
definitely works for the fish, and some people do very well with
their plants in peat water too. It's just that the carbonate
hardness/CO2 "rules" that we've learned are no longer applicable
What absolutely _doesn't_ work is the use of "water softening
resins" which replace calcium ions with sodium. Soft water fish
are no happier with all that salt than they were with the
hardness. And, to get back to where we started, the pH value
itself is of much lower importance than the hardness. If you get
the water soft enough to get the fish spawning, it is unlikely
that the pH will remain high enough to be of any trouble
whatsoever. The addition of pH reducing chemicals (other than
CO2) is just not necessary, and can lead to unexpected and
Adding more chemicals to hard water to try to replicate the
extremely pure water conditions that soft water fish come from is
Aquatic Gardeners Assoc.