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Re: [APD] Actinic light and semantics

I don't disagree with your results Tom. And my much more
meager experience certainly doesen't present anything but

I haven't met Dr. HOvenac myself but I know some folks who
have and the seem to a lot of respect for him -- which is
not to say they agree with him all the time. [I did once
talk to a customer rep at Hagen that couldn't say enough
bad about Hovenac's papers re biofilter bacteria but he was
sore about what was implicit in those papers about Hagen's
bio boosters.]

I don't know how he came by his claim, but I don't think it
is disingenuous. And I doubt that it's part of a marketing
scheme from Marineland -- I don't think they put any
actinics in their Eclipse hoods. They barely put in enough
light of any kind [Of course, like most general market
hoods, they're not designed specifically for plants but for
low maintenance]. 

I'm not saying that anyone said he was disingenuous. I'm
just saying an actinic bulb's output is in the range of the
spectrum that plants use *but* only one part and I doubt
that an actinic bulb plus a triphosphor bulb or 50/50
actinic bulb and a triphoshor bulb will do much for plants
that you can't do with good quality triphosphors. But an
actinic does take up a whole slot that could be used by a
more balanced output bulb. So I doubt that, watt for watt,
putting in actinic bulb in the mix will help. Thus, I doubt
that it's is something one *should* do. 

I do know someone that was burning actinics with his
triphosphors and when he replaced the actinics with
triphosphors, the plants seemed to improve, as if
responding to "more light." Not that that proves much --
lots of stuff going on an aquarium.

Maybe Hovenac wrote the article a long time ago. Why do I
say this? Because he mentions Aquasuns as 5000 K bulbs. I
assume he means the URI bulbs with the model name
"Aquasun." These haven't been rated at 5000 K for several
years. A big blue peak has been added and they are rated at
10000 K.

BTW, they are a very nice bulb as NOs and VHOS go -- very
good color rendition, appearance, plant growth -- adding an
actinic might spoil at least two out the three.

good luck, good fun,
Scott H.
--- Thomas Barr <tcbiii at earthlink_net> wrote:
> "Plant lamps are designed to emit light at the red
> wavelengths to duplicate the job of the sun. But too much
> red color can cause aquatic plants to grow tall and thin.
> For best results, use a daylight (5,000 K) lamp such as
> an
> Aquasun, Ultralume 50 or Chroma 50 in combination with an
> actinic white or actinic day lamp. The actinic day or
> white
> lamp is a mixture of 50% actinic (blue light) and 50%
> daylight."
> I disagree with him about a 5000K bulb being something
> that will yield thin
> tall growth which is what this statement __seems to
> suggest___ . He did not
> come out and say but the suggestion is very strong.
> Some semantics here. "But too much red can cause the
> plants to grow tall
> and thin" .
> He did not come out and say 5000K or cool white bulbs
> cause this type of
> growth. 
> But it does sound like 5000K causes leggy thin growth
> doesn't it?
> Light bulb makers, Cables, algae miracle cures and all
> sorts of consumer
> products such as the Cladophora pills or Hydrilla pills
> that turn limpness
> into wild sex animals of lust and passion and makers of
> various snake oils
> all tend to play these word games. Spam anmd scams also
> tends to contain
> large amounts of this language.
> Folks need to be careful and read what it is that is
> really being said.
> I'd like to see some research __clearly__ showing this to
> be
> significant(5000K vs a 5000K plus an actinic) before I'd
> believe this
> concerning aquatic plants. 
> I have my proof to the contrary and my experience using
> cool whites. I used
> a 50:50 daylight, actinic bulb for a couple of years so I
> know both sides
> of this coin. 
> Dr Cain(Micro propagation research namely on Orchids and
> aquatic plants)
> uses the cool whites so it's specifically on aquatic
> plants, Robert Hudson
> had dug up a good paper on the use of cool white in
> growth studies and had
> posted it on his site about a year or so ago.
> .That is a good study and would be tough to argue against
> based on folks
> experiences and the theory when looking at aquatic plant
> photosynthesis and
> their LHC's.
> I have at least a dozen research papers on aquatic
> photosynthesis sitting
> around my place. 
>  Actinics have a dagnasty blue spike and not much
> else(virtually all the
> energy is all centered around the blue range(no red,
> yellow, green at all
> pretty much), 10K bulbs and most other bulbs have other
> portions of the
> emission spectrum that balance the blue with red etc.
> I'll give him the benefit of doubt and assume he's
> suggesting that a mix of
> bulbs will give a good balance to the eye and the growth
> of plants. An
> Actinic with say several(3) 5000K bulbs would give a good
> mix perhaps, but
> actinics are not particularly useful as they put all the
> energy into a very
> small blue range with not much else which is ideal if you
> live 10-20 meters
> deep in __clear__ water like coral. 
> Virtually all aquatic plants live in the top 1-2 meter or
> so although you
> may find them deeper but the best growth is near the
> surface, not down
> deep. Few folks have tanks over 1 meter.
> Will actinics hurt?No, will they help more than a
> 6000-6700 K bulb? No.
> Would you be able to tell the difference as a hobbyist
> between a tank with
> 2 x 5000K and an Actinic vs a 2x 5000K and 6700K? I doubt
> it. 5000K and
> 6500K bulbs are cheap and easy to find, actinics are all
> specialty bulbs
> that generally cost a fair amount more. Marineland owns
> companies that sell
> aquarium specific bulbs. 

S. Hieber

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