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Abstract Questions from a Freshwater Aquarist
7/31/09
Hello.
<Hi,>
I just have a couple of questions that I couldn't seem to place under
the same category (hence the name). Okay, my first question is
can ph kill fish?
<Yes. Rapid changes alters blood pH, and this turn affects the ability
of the blood to carry oxygen and carbon dioxide around the body. The
wrong pH will severely stress, eventually kill, those fish adapted to
particular pH levels. A Rift Valley cichlid for example will not do well
at pH 6, and will become much more prone to opportunistic infections
than otherwise.>
I recently bought 5 goldfish for my aquarium, I set the bags in the
water for 15 minutes, then netted the fish and put them in my aquarium.
Three hours later (literally) they all died. I checked my water
chemistry soon
after, and the only offending thing I could see was a ph below the
charts (anywhere from 5-5.4, judging by the color) Nitrate: 40 Nitrite:
0 Ammonia: 45-ish Hardness: Moderate Temperature: about 76 at time of
death.
<Goldfish will tolerate pH values across a broad range, at least for a
while, but they do best at basic pH levels between 7 and 8. If your pH
really was as low as 5, then [a] biological filtration wouldn't be
working,
and [b] that low pH could easily have shocked or killed the Goldfish
outright.>
My second question: are store-bought fancy guppies of poor (I
mean very poor) quality?
<Can be. Essentially the question is the same as this: which are hardier
and more long lived, pedigree dogs or mongrels? The answer is of course
mongrels, which, on average, consistently outlive their pedigree
cousins.
Guppy breeders select in favour of certain traits, such as tails of a
certain length, or particular patterns on the body. But they don't
select in favour of hardiness or longevity By contrast, evolution
selects in favour of "fitness", the ability to survive and breed.
There's actually good experimental evidence that supports this. Fancy
Guppies cannot be acclimated to living in seawater, whereas wild Guppies
and "feeder" Guppies
both can. In other words, when breeders create Fancy Guppies, they seem
to throw away some of the genes that made Guppies hardy in the first
place. Now, there are differences in quality of Guppies just as there
are differences in the quality of pedigree dogs. The Guppies you buy
from a pet store were bred to a price, not a quality, and often fish
farms use antibiotics to "support" their fish so that they can stock
lots of them in breeding ponds without being too worried about
healthcare. By contrast, breeders at fish clubs will be taking more
care, selecting the best fish, and looking after each group of fish
carefully, as a labour of love. None of this gets away from the fact
that Fancy Strains are often very inbred, with father-daughter,
mother-son crosses being very common, so even under the best of
circumstances, Fancy Guppies are genetically "weak". But there is a
difference between good quality fish and mass produced fish.>
I've heard that the guppy is supposed to be the easiest and most
enjoyable fish in the hobby, and yet I've also had experience (and read
on other sites) that suggests otherwise, mostly due to inbreeding and
the breeders only selling low-quality fish to pet stores.
<Pretty much. Wild Guppies are astonishingly adaptable, and that's why
they became popular in the first place. Fancy Guppies, like fancy
varieties of most aquarium fish, are much less adaptable.>
My third question is if I breed natural (feeder) guppies with Fancy
guppies, will (some of) the fry be fancy and hardy?
<No; they'll all be "feeder" Guppies, or at least, mongrel Guppies with
a mish-mash of colours. To my eyes, such Guppies are lovely, resembling
the wild-type fish, which are wonderfully variable. The old name for
Guppies, Millionsfish, referred to the fact that there were so many of
them, and every one was different.>
My last question is that I've heard (on this site and others) that
Hornwort is an amazing and under-appreciated plant.
That it eats up Nitrates and Ammonia, looks good, reduces water
hardness, sucks up CO2, puts in O2, increases water ph, and is easy to
keep. How many (if any) of those things are true?
<Like high-fibre breakfast cereals, while it certain does some good, it
isn't a magic bullet that will cure all life's ills! Hornwort, or
equivalent floating plants such as Floating/Indian Fern or Amazon
Frogbit, are great additions to tanks with livebearers. Your Guppies
will nibble at them directly, and also peck away at algae growing on the
roots. Yes, they absorb some nitrate (and even ammonia) at a rate
depending on light
intensity (i.e., growth rate) and yes, floating plants provide excellent
hiding places for newborn fry. I strongly recommend them, but I would
expect them to replace your standard protocols for water quality and
water
chemistry management.>
I'm looking for a beneficial plant to re-place my withering ones (might
help those plants if I turned off/down my air-stones), and then stumbled
across the Hornwort.
<Hornwort does need strong lighting at tropical temperatures. It's less
demanding in coldwater tanks and ponds. In tropical tanks, sometimes
wastes away if the lighting is poor to moderate. Indian Fern and Amazon
Frogbit are, in my experience, a bit more forgiving.>
Hope I wasn't any trouble!
-Koda
<Cheers, Neale.>
Plant Basics - 10/21/2006
Hi,
<Hello.>
I just bought some hornwort for my 29 gal aquarium. I have about 1 tbsp per 5
gallons for my Mollies and Patties.
<I assume that you mean 1 Tbsp of "salt" per 5 gallons.>
How do I take care of the plant? I mean do I need to fertilize or anything else?
<Likely not. This plant, if left floating, is typically very easy to care for,
but can "fall apart" without enough light, especially if you try to get it to
root.>
Is this considered a brackish water aquarium?
<Mm, probably not, but many plants will not like that much salt. Hornwort
should do okay, though.>
I shut off my air pump because I read it will hinder plant growth, is this true?
<Well, yes, in a way. Aeration can allow more CO2 out of the water than you
might desire, since plants consume CO2. But for just some hornwort, you'll be
fine to leave your aerator running.>
I was hoping I could get some answers; every where I look I can't seem to get
the answers I'm looking for.
<Try "Encyclopedia of Aquarium Plants" by Peter Hiscock. This is a GREAT book
for someone who really wants to get into plants and is just starting out with
them.>
I like the look of the real plants and the idea of having a aquarium that is as
natural as possible.
<Yup, you'll love that book.>
Hope you can help! Thanks, -B.C.
<All the best to you, -Sabrina>
Hornwort as a Water Softener?
Hello WWM Crew, An uncharacteristically brief questions from me, this time.
I have
read in a few places that hornwort will soften water. Is this true? If
so, should I remove it from my cichlid tanks? Thanks, Ben
< This is really an amazing plant that doesn't get enough credit. I saw hornwort
all over the bays and inlets in Zambia while diving in Lake Tanganyika a few
years ago. It looked like little wire brushes. When I returned I read up on this
plant and found out that it actually gets its carbon dioxide from breaking down
the bicarbonate in the water. Pretty amazing. During the process CO2 is removed
and you get a calcium carbonate that actually increases the pH. Since coming
back I have added hornwort to all my African tanks because they can handle the
hard water and do a great job absorbing nitrates from the water.-Chuck>
Growing (or not) hornwort
I must be the only person that can’t grow hornwort!!
I read the bit on people trying to eradicate it and had a laugh. Does it
need high levels of nitrate?? Since my vals, hygros, java ferns and
anubias have become established in my tanks, the hornwort is struggling.
It gets lots of light and I fertilize weekly with Hagen Plant pro as
well as use Jobes spikes under the gravel for the vals and hygro. When
the tanks were cycling the hornwort grew so fast I had to toss out scads
of it. Alas no more.
Is it a lack of nitrates??
< Could be a couple of things. Hornwort is found all over the world and adapts
to different conditions. I found some in Lake Tanganyika in Africa. First
question is how old are your light bulbs. Lights loose intensity over time. Any
bulbs over 6-12 months old should be replaced. Second is the other plants are
now competing with your hornwort for nutrients and they are probably better
adapted to absorb nitrates then the hornwort. Based on what you have stated it
sounds like the hornwort likes ammonia created during the cycling stage better
than the nitrates in the established tank. Sometimes the variety of hornwort we
commonly get in the aquarium trade does not do well in warm water tanks.-Chuck>
Thanks
Julie Riley
Hornwort and salt
Hi from New Zealand
<Hello from sunny Southern California>
We (the Department of Conservation) are contemplating using salt to eliminate
Ceratophyllum demersum (hornwort).
<Mmm, this is Bob (Robert) Fenner... a long time pest control applicator and
advisor licensee... someone had to qualify for our company's service division...
and past member of Aquatic Plant Management Society, et al. organizations...
involved in Hydrilla eradication programs here... and an all-round pet-fish sort
of guy... who has cultured, sold large amounts of this plant (aka Coontail to
folks here in the States). Not easily controlled with salt... we can/should talk
over other control mechanisms... including commercial herbicides.>
Hornwort is presently New Zealand's most invasive exotic macrophyte. Although
hornwort has been present in the North Island since the 1960s, it has only
recently made it to the South Island.
<This stuff "really gets around"... like many other pest macrophytes via fishing
gear, waterfowl... even ornamental aquatics mis-use (release to the wild)>
Hornwort is a multi-million dollar pest for North Island hydro-electric power
generators, principally because it causes blockages in dam turbines (the scope
for disruptions to South Island HEP schemes is potentially even
greater). Hornwort is also capable of displacing the majority of our native
macrophyte species and even some of our most invasive introduced macrophytes
including Egeria, Elodea, Lagarosiphon.
<Does so in the U.S. as well>
Fortunately eradication a still a realistic option (in the South Island) because
of the limited extent of the present infestation. A number of control options
are being evaluated, the most promising of which is soil sterilization using
salt (i.e. sterilizing the streambed substrate). We have been able to desiccate
the majority of the plant the floating-above ground component) using the contact
herbicide reglone (a form of diquat).
<Really... this is the product category (teratogens) I was going to describe...
can you related the treatment protocol? Are you using a spreader-sticker? Need
to know water temperatures, if you're spraying emergent material...>
However, there is still the possibility of buried propagules withstanding a
herbicide treatment hence, we need a soil sterilent that is inert (when in
contact with organic matter) and which has a residual action such that it would
saturate the streambed and eliminate any remaining viable buried fragments.
<Mmm, yes... but a systemic might likely prove more effective...>
Salt appears ideal in this respect particularly as trials have shown
free-floating hornwort will perish if immersed in water of sufficiently high
salinities.
<Yes... but for how long, how high a standing salinity... what about the
residual salt?>
I was alarmed to learn that hornwort is included amongst a list of macrophytes
that are suitable for brackish aquaria.
<Yes, exactly... it is>
Do you consider that it is realistic to expect that, if applied at sufficiently
high salinities, salt will also successfully eliminate buried propagules (given
hornwort's tolerance of brackish water)?
If so at what concentrations (parts per thousand) should salt be applied?
<Obviously, the only treatment regime I would trust is one that was tested out
by assay... I would do a few experiments here... Unfortunately I know
Ceratophyllum can be almost instantly placed from fresh to water of a spg. of
1.005... likely higher salt concentrations, w/o suffering apparently.>
I really appreciate your help.
Kind regards
Matt Bloxham
Biosecurity Contractor
Department of Conservation
Motueka Area Office
New Zealand 00 64 3 528 1810
<Do try a few test plots... Again, I would utilize the Diquat (but can suggest
other products...) with an oil... on emersed portions at standard dosage...
during mid-day to afternoons, at temperatures of 55 F. or higher... Much to
discuss re the allowance of other economic poisons in NZ, and concerns re
run-off, toxicity issues... Am interested (parenthetically) if you've considered
triploid carp species as bio-controls?
Bob Fenner>
Hornwort eradication options
Hi Bob,
Thanks for such a prompt reply, couldn't believe it when I got back from lunch
to find your message.
<We aim to please... and must need reply ASAP or get hopelessly buried>
We used a spray contractor to apply the reglone. He used an Aquagel formulation
which was administered in 600mm wide strips (with 1m spacings) across the
stream.
<At about 1 gallon per...? Surface area.>
At the time hornwort was at maximum biomass. Smaller infestations amongst
willows were spot sprayed. Temperatures were in excess of 15 degrees Celsius
(i.e above the recommended minimum operating temp forreglone) and spraying
commenced in the morning to avoid problems with
thermoclines.
<Mmm, I am not so much inclined to be influenced by the last... more important
that the weed be active metabolically... late morning to mid afternoon on sunny
days>
The worst affected stream section has significantly reduced flow with large
areas of standing water (i.e. plenty of herbicide contact time) and was not at
all turbid. It has been nine months since the Aquagel was administered and there
is still no sign of hornwort regrowth.
<Good>
We are just coming into summer and in New Zealand, hornwort typically reaches
maximum biomass in Autumn.
<Yes, same here... late summer into mid-autumn>
The contractor believes that the reglone will eliminate the hornwort completely
but we have reservations because of the issue of buried fragments which the
reglone is unlikely to touch. Unfortunately there are no systemic aquatic
herbicides presently registered for use in New Zealand.
<Ahhh... a shame. Shortsighted... more pollution, trouble from their lack of
availability, use.>
We have certainly thought about using triploid grass carp, but decided against
for the following reasons:
This control option would involve significant habitat manipulation. For example,
shallow areas of Moutere Stream would need to be deepened.
<Really? Have seen the big three species used in very shallow waters... even
have some footage of a Ctenopharyngodon "going terrestrial"! to get at shoreline
growth.>
If this control method were to prove unsuccessful, deepening stream sections may
increase the suitability of these areas for further hornwort infestation (by
slowing flow and increasing the rate of mud deposition).
<Possibly>
* Use of grass carp would rule out the option of simultaneously treating Moutere
Stream's hornwort and pest fish populations (using the same methods). Grass
carp could only be introduced into Moutere Stream after attempts to eradicate
pest fish had been concluded. Any pest fish eradication attempt would ideally
involve significantly dropping the water level (in addition to applying a
piscicide) which would benefit other hornwort eradication options but not the
grass carp control option.
* We understand that Grass carp are inefficient digesters of food; half of the
weed eaten may pass through the gut undigested. Hence, there are doubts over
whether grass carp are able to digest/process hornwort sufficiently to
neutralize any viable propagules. The widespread dissemination downstream of
partially digested vegetative matter/propagules is undesirable in a running
water system such as Moutere Stream.
<Would only establish a predator-prey equilibrium/dynamic>
* The introduction of yet another exotic fish species to this stream: runs
counter to the Department's objective of minimizing impacts from introduced
freshwater fish species in the Nelson region as the stream already contains a
significant biomass of tench and Gambusia.
We intended dewatering the affected stream section using a weir and pumping to
land so that the salt could be applied directly to exposed streambed, as we
figured this would help maintain salt in its most concentrated form. We will
certainly look at testing the salt by assay.
<Only way to assess practicality, effectiveness.>
Meanwhile, if you can think of any other way of eliminating the hornwort
outright (including the buried component), we would certainly love to hear back
from you (it is unfortunate that systemic herbicides are not an option for us).
<Well... is the area involved absolutely huge? Have you done any testing re how
deep the propagules are/might be? Another possibility (has been used for
Hydrilla verticillata infestations in areas in excess of 50 hectares...) is to
de-water, Vapam with cover (optional), scrape and remove sediment... to waste,
fill areas... even to the sea... Expensive, drastic... but another possibility.
Bob Fenner>
Thanks again for your help Bob.
Kind regards, Matt Bloxham
Looking for Hornwort/Coontail/Ceratophyllum demersum...
I would like to know if you can buy the Coontail/hornwort at a store. If
not, is there any way to grow this plant? please send a reply.
<Ceratophyllums grow very well in most any type of hard, alkaline water with
sufficient light. This is a popular genus of aquatic plant in many places around
the world. Bob Fenner>
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