Aquaponics Digest - Fri 03/20/98
Message 1: Re: Water hardness/fish tolerance, was Re: Partial Water Changes
from Chuck Hicks
Message 2: Re: Water hardness/fish tolerance, was Re: Partial Water Changes
from Jackie Jones
Message 3: Re: Water hardness/fish tolerance, was Re: Partial Water Changes
from james.rakocy@uvi.edu (James Rakocy, Ph.D.)
Message 4: CO2 Production, was Re: Water hardness/fish tolerance,
from Gordon Watkins
Message 5: Re: Seaweed Extract addition for aquaponics systems
from Gordon Watkins
Message 6: Re: Aquarium Plants
from Gordon Watkins
Message 7: Re: Seaweed Extract addition for aquaponics systems
from John Shannonhouse
Message 8: Re: Aquarium Plants
from "Wendy Nagurny"
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Subject: Re: Water hardness/fish tolerance, was Re: Partial Water Changes
From: Chuck Hicks
Date: Fri, 20 Mar 1998 08:37:34 -0600
S & S Aqua Farm wrote:
>
> At 05:01 PM 3/9/98 -0500, Wendy wrote:
> >Thanks for answering my questions. I have more.
> >
> >Do the plants also absorb the calcium etc. in the water too? In areas
> >which have hard water, just adding to replace what is naturally lost
> >through evaporation/respiration would result in the hardness gradually
> >creeping up -- sometimes to incredibly high levels. This usually wouldn't
> >be noticed in existing fish, as they will become accustomed to it (until it
> >got VERY hard), but it would shock any new fish that are added.
>
> I'll have to leave the answer to this to those with more research and
> analysis experience. We haven't experienced a noticeable problem when
> adding new fish to the existing system, even though the majority of our fish
> have traveled under stressful conditions (by air, in a bag/box combination
> for a 24-48 hour period, depending on the airlines).
>
> My opinion is that the system itself is modifying the potential calcium
> buildup in the bacterial breakdown phase to somehow eliminate the problem.
> Other opinions or data would be welcome here.
>
> Paula
> S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775 417-256-5124
> Web page http://www.townsqr.com/snsaqua/Moderate levels of calcium and
magnesium bicarbonate and carbonate
alkalinity are very beneficial for fish in recirculating systems.
Alkalinity provides a buffering system preventing rapid flucuations in
pH. Low alkalinity water, less than 5 ppm. are actually a greater
stress on fish than higher levels. Bicarbonate buffers waters
against sudden changes in pH. There can be a difference in hardness and
alkalinity especially if the hardness components are alkaline earth
substances. A hard water does not always indicate high alkalinity.
When total hardness and total alkalinity are equal calcium and magnesium
are totaly associated with bicarbonate and carbonate. When total
alkalinity is higher than hardness than bicarbonate and carbonate must
be associated with other availabe minerals such as potassium and sodium.
When total hardness is greater than alkalinity calcium and magnesium
can be associated with sulfate, chloride, silicate or nitrate.
Alkalinity is important in recirculating systems because there is a
normal build up of carbon dioxide and in some systems the carbon dioxide
must be removed by aeration or other methods. Carbon dioxide is a
source for acid formation and can cause depressions in the pH.
Paula, I trust this explanation will be helpful to some of the
subscribers.
Chuck Hicks
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Subject: Re: Water hardness/fish tolerance, was Re: Partial Water Changes
From: Jackie Jones
Date: Fri, 20 Mar 1998 11:26:07 -0800
Please cancel
S & S Aqua Farm wrote:
>
> At 05:01 PM 3/9/98 -0500, Wendy wrote:
> >Thanks for answering my questions. I have more.
> >
> >Do the plants also absorb the calcium etc. in the water too? In areas
> >which have hard water, just adding to replace what is naturally lost
> >through evaporation/respiration would result in the hardness gradually
> >creeping up -- sometimes to incredibly high levels. This usually wouldn't
> >be noticed in existing fish, as they will become accustomed to it (until it
> >got VERY hard), but it would shock any new fish that are added.
>
> I'll have to leave the answer to this to those with more research and
> analysis experience. We haven't experienced a noticeable problem when
> adding new fish to the existing system, even though the majority of our fish
> have traveled under stressful conditions (by air, in a bag/box combination
> for a 24-48 hour period, depending on the airlines).
>
> My opinion is that the system itself is modifying the potential calcium
> buildup in the bacterial breakdown phase to somehow eliminate the problem.
> Other opinions or data would be welcome here.
>
> Paula
> S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775 417-256-5124
> Web page http://www.townsqr.com/snsaqua/
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Subject: Re: Water hardness/fish tolerance, was Re: Partial Water Changes
From: james.rakocy@uvi.edu (James Rakocy, Ph.D.)
Date: Fri, 20 Mar 1998 13:03:49 -0400 (AST)
carbonate
>alkalinity are very beneficial for fish in recirculating systems.
>Alkalinity provides a buffering system preventing rapid flucuations in
>pH. Low alkalinity water, less than 5 ppm. are actually a greater
>stress on fish than higher levels. Bicarbonate buffers waters
>against sudden changes in pH. There can be a difference in hardness and
>alkalinity especially if the hardness components are alkaline earth
>substances. A hard water does not always indicate high alkalinity.
>When total hardness and total alkalinity are equal calcium and magnesium
>are totaly associated with bicarbonate and carbonate. When total
>alkalinity is higher than hardness than bicarbonate and carbonate must
>be associated with other availabe minerals such as potassium and sodium.
> When total hardness is greater than alkalinity calcium and magnesium
>can be associated with sulfate, chloride, silicate or nitrate.
>Alkalinity is important in recirculating systems because there is a
>normal build up of carbon dioxide and in some systems the carbon dioxide
>must be removed by aeration or other methods. Carbon dioxide is a
>source for acid formation and can cause depressions in the pH.
>
>Paula, I trust this explanation will be helpful to some of the
>subscribers.
>
>Chuck Hicks
An additional note:
Do not let your pH fall below 7.0 because nitrification efficiency, the
conversion of ammonia to nitrite to nitrate by bacteria, declines
dramatically. Nitrification stops when pH is below 6, and ammonia will build
up rapidly. However, it will be in the non-toxic ionic form - NH4+. I once
had ammonia-nitrogen levels at 169 mg/L without any problem as long as the
pH was low. If pH increased 0.1 units, the fish went off feed immediately as
NH4+ shifted to NH3, toxic ammonia gas (2.4 mg/L is lethal to tilapia). If
you discover that your pH is in the 5 range, chances are that a large
reservoir of NH4+ has accumulated. When you add a large amount of base to
rectify the problem (bring the pH to 7), the fish will literally jump out of
the tank in one massive explosion as they are zapped by the instantaneous
conversion of NH4+ to NH3. Add the base very gradually over days until you
reach pH 7.
As for carbon dioxide, have plenty of aeration to blow it out of the water
into your greenhouse where it can increase plant growth rates by up to 30%
as many studies have shown. If CO2 accumulates in the water above 20 mg/L it
will slow fish growth, even kill them at high levels, as CO2 will interfere
with the fishes ability to absorb oxygen through their gills. In pure oxygen
systems the accumulation of CO2 is a big problem because diffused aeration
isn't used to avoid stipping the high levels of dissolved oxygen from the
water. Chemicals can be used to convert CO2 to bicarbonate and carbonate
alkalinity, but alkalinity levels become astronomically high - 700 to 800
mg/L or more. Special areation zones/towers are established to "sparge" the
CO2 from the water.
Jim R.
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Subject: CO2 Production, was Re: Water hardness/fish tolerance,
From: Gordon Watkins
Date: Fri, 20 Mar 1998 14:17:48 -0600
Jim, your and Chuck's explanations of the inter-relatedness of pH,
alkalinity, hardness, ammonia and CO2 was very enlightening. Thanks to
both of you for taking the time to explain it so well. It confirms my
belief that the hard, alkaline, high pH water that we have here in the
Ozarks is well suited for aquaponic systems.
Do you have any figures on just how much CO2 per lb of fish is produced
by tilapia in recirculating systems? Conventional greenhouse growers go
to great expense to inject CO2 into the greenhouse atmosphere and it
would be interesting to know how much benefit in this regard the
fish provide.
Regards,
Gordon
James Rakocy, Ph.D. wrote:
>
>> As for carbon dioxide, have plenty of aeration to blow it out of the water
> into your greenhouse where it can increase plant growth rates by up to 30%
> as many studies have shown.
>
> Jim R.
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Subject: Re: Seaweed Extract addition for aquaponics systems
From: Gordon Watkins
Date: Fri, 20 Mar 1998 14:30:51 -0600
Thanks for the info, Paula.
The use of seaweed for plant growth has long been a controversial
subject, but I've used foliar sprays containing seaweed on my field
crops for over 20 years and I concur with the Kruzens. Besides
containing trace amounts of nearly all of the minor plant nutrients, it
is also claimed to contain the growth stimulants auxins, giberrelins,
and cytokinins, although it is debated as to whether these stimulants
remain active after the manufacturing process. Supposedly, the liquid,
cold-processed seaweed concentrates contain more active hormones and
enzymes that the dried, heat processed forms like Maxicrop. I plan to
try some Algamin, a liquid form, in my system soon and I'll let you know
if anything noticible occurs.
Regards,
Gordon
S & S Aqua Farm wrote:
>
>
> Gordon - using the granulated formula diluted to concentrate (the
> concentrate formula, I believe, calls for 2 Tbl per gallon of water for
> foliar spray), we add approximately 1 cup into our 800 gallon tanks. I
> don't "know" that you can "overdose" the system with too much, as primarily
> what it provides is the enzyme for the plants to uptake available nutrients,
> but suppose it is possible.
>
> The outside organic growers who first introduced us to Maxicrop (Tom and
> Angel Kruzen - I think you know them) said they saw visible differences in
> yield and general health of their plants. Knowing their operation, I would
> say that the plants had proper nutrients for good growth, but the Maxicrop
> resulted in a substantial boost in the plant's ability to use them.
>
>> Paula
> S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775 417-256-5124
> Web page http://www.townsqr.com/snsaqua/
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Subject: Re: Aquarium Plants
From: Gordon Watkins
Date: Fri, 20 Mar 1998 14:46:50 -0600
Wendy,
It was unclear to me from you post whether you're growing your aquarium
plants in a submerse state in aquaria or emersed in beds. Could you
please clarify? I've been growing some Hygophila stricta in my beds and,
following a couple of days of transplant shock after being moved from an
aquarium, it's been growing very well for several months now and is
blooming. I've taken cuttings which I've reintroduced to the aquarium,
but my angelfish liked it so much they stripped it to the stems within a
few hours! Your comments about its use as an indicator plant wer
interesting. I'll have to monitor it more closely. I've also tried
Crytocoryne wendtii, but with less success. I think perhaps it is a more
submerse species. Do you know of a good reference that shows which
plants require (or tolerate) an emerse phase? How about Java fern?
Incidentally Paula, aquarium plants don't have to be submersed in water
for transport to market. They can simply be wrapped in wet newspaper and
protected from freezing.
Regards,
Gordon
S & S Aqua Farm wrote:
>
>
> >I'm not sure about the nutritional differences, but I certainly recommend
> >raising aquatic plants for the home aquarium trade. I raised water sprite
> >and several species of Hygrophila, and a friend raised Java fern. Nether
> >of us ever had any problem selling our plants. Water sprite requires a
> >high level of nutrients in the water or it just languishes. It a real good
> >seller because it doesn't ship well so most petshops and distributors
> >cannot get nice plants. It disintegrates very fast if kept out of light
> >for long. Many pet shops usually don't carry it because of the condition
> >it usually arrives in. So if you have a distributor near by, that you can
> >deliver small quantities often you will have a good customer.
>
> Thanks for the input on your aquarium plants - makes it sound like a great
> idea to grow, then ship in water-filled containers to a local market.
>
> Hygrophila,
> >I have noticed, is a good indicator of water quality. If the ammonia or
> >nitrite levels start to creep up, it begins to look sickly and put out
> >small leaves, even before my fish would act bothered. Java fern is a hardy
> >slow grower that is not bothered by most plant-nibbler fish. The wholesale
> >prices it gets reflects its slow growth nature.
>
> Sounds like a great indicator plant that would enable growers to "advance"
> monitor water quality - especially helpful - thanks!
>
> >
> >Most plants in the hobby trade are actually bog plants and require a period
> >of emersion in order to bloom and set seed.
> >
>
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Subject: Re: Seaweed Extract addition for aquaponics systems
From: John Shannonhouse
Date: Fri, 20 Mar 1998 16:18:45 -0600
Hello,
On 20 Mar 1998, Grdon Watkins wrote:
<>
People have been writing about enzymes being added to a growing
system in seaweed extracts. Exactly what kind of enzymes are supposedly
being added? I cannot think of any benefit any kind of enzyme would
provide just floating around in the fish tank and hydroponic beds.
<>
Is it such a good idea to be adding plant hormones to your growth
beds without knowing their relative concentrations and activities?
Different plant hormones also stimulate growth in different (not always
desirable) ways. You could cause your plants to waste a lot of energy
growing long roots and shoots with giberellic acid or cause a plant to have
trouble telling up from down with auxin.
Just something to keep in mind.
John Shannonhouse
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Subject: Re: Aquarium Plants
From: "Wendy Nagurny"
Date: Fri, 19 Dec 1997 05:59:37 -0500
Gordon,
Right now I don't have ANY aquaria :-( (I still go into shock on occasion)
When I did, I grew all my plants submersed. I raised for sale Hygrophila
polysperma and Water Sprite (Ceratopteris thalictroides). Sometimes my
Hygrophila would grow up out of the water, but if it managed to cascade
over the side, the leaves would get all ugly from lack of humidity. They
were in my house, not in a proper greenhouse.
Did your angelfish actually EAT all of it, or did they just shred it up? I
thought that freshwater angels usually only picked at greens (but they DO
enjoy their toys). Silverdollars usually won't leave anything green
uneaten though.
Cryptocorynes in general have a reputation for being temperamental even
when submersed. I do believe they do have an emersed phase though, because
since they don't produce bulbletts in abundance, they are usually
propagated from seed. I have never tried to grow Java fern emersed, but
they are a very hardy and tolerant plant so you might have luck.
As far as publications, contact TFH. They publish a lot of books that are
more on the professional level that they do not readily advertise. I would
guess that they would have a good one on plant propagation.
Except for propagation from seed (ie your crypts), why would you want to
grow these plants emersed? Hygrophila propagates easily from submersed
cuttings, as do many other aquarium plants. Or is this just for the fun of
it. Then you don't need a reason. :-)
----------
> From: Gordon Watkins
> To: aquaponics@townsqr.com
> Subject: Re: Aquarium Plants
> Date: Friday, March 20, 1998 3:46 PM
>
> Wendy,
> It was unclear to me from you post whether you're growing your aquarium
> plants in a submerse state in aquaria or emersed in beds. Could you
> please clarify? I've been growing some Hygophila stricta in my beds and,
> following a couple of days of transplant shock after being moved from an
> aquarium, it's been growing very well for several months now and is
> blooming. I've taken cuttings which I've reintroduced to the aquarium,
> but my angelfish liked it so much they stripped it to the stems within a
> few hours! Your comments about its use as an indicator plant wer
> interesting. I'll have to monitor it more closely. I've also tried
> Crytocoryne wendtii, but with less success. I think perhaps it is a more
> submerse species. Do you know of a good reference that shows which
> plants require (or tolerate) an emerse phase? How about Java fern?
> Incidentally Paula, aquarium plants don't have to be submersed in water
> for transport to market. They can simply be wrapped in wet newspaper and
> protected from freezing.
> Regards,
> Gordon
>
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