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Crypts and Light



Cathy Hartland wrote:

>Now, for crypts, a 
>different set of rules seems to apply. But there again I have 
>purchased crypt plants which were grown under low light and were 
>totally green, and had them turn deep blood red in my tank with 
>higher lighting (admittedly there could have been other factors 
>involved). 

This has nothing to do with the amount of light in your tank.  Commercially
grown Crypts are grown emersed, and almost all of them are green.  Some
then turn red, brown or purple in submersed culture.  It has been my
experience that many of the red/bronze Crypts get their deepest, best color
under fairly low light conditions, although this may be at least partly
because they don't have as much nutrient competition at these light levels.

>Just for completeness, here are my tank stats: one tank 30 long @ 
>4 watts/gal (don't cringe, it's a leftover light setup from a reef tank - 
>and it grows beautiful plants), 

There is absolutely no question that you _can_ have a beautiful palnted
tank with very high light levels... The question is, is there anything you
are growing at this level that could not be grown very well at lower light
levels?  And if not, does it make sense to throw our limited resources away
in this fashion?  Obviously, even running a tank uses energy, and
everything we do every day has some impact on our environment.  Everyone
has to decide for themselves whether the benefits outweigh the costs.  I
think we need to think about it, though, and make a rational decision
rahter than just buying into the "more is better" mentality.  (I'm not
accusing you of that... you may have gone through this thought process
already.  I'm just asking each aquarist to do it for themselves)

>and one 40 high @ 3 watts/gal. No 
>reflectors, just white paint. In the latter tank I recently replaced 2 
>coralife 50/50's (there for color balance with the trichromatics) 

The idea of "balancing" color with mixtures of tubes is a tricky one.  If
your goal is to balance the color in terms of eye-appeal, that's fine.  If
the goal is to somehow "balance" the color for the plants, you are fooling
yourself.  The plants that are under the blue tubes will get the blue
light, and those under the pink tubes (or whatever) will get the pink light.

>with Ultra Tri Lux (a fine bulb!) and the difference in light level is
marked. 
>The plants notice it too. It's still 3 watts/gal, but it means 
>something entirely different than it did before. 

If your plants improved in growth with the change in bulbs, that is a good
indication that it was a good choice.  Don't, however, be fooled because
the tank "looks" brighter.  The part of the spectrum that we see best,
(green light) is exactly the part of the spectrum that plants use least.
So just because a bulb "looks" brighter, has no direct bearing on its
ability to grow plants.  Some of the "dimmest" looking, purplish bulbs grow
plants very, very well, if you don;t care how the tank looks ;-) 

David Grim wrote:

>I have about 5 watts/gallon VHO full spectrum lighting on my 125 and 65 
>gallon densley planted tanks. Icecap ballasts. CO2 injection. TMG 
>supplementation. No algae except a small bit of BBA in the overflows where 
>the SAEs and shrimp can't get to it. The reds seem to intensify with this 
>light level. Riccia grows like crazy. 

I hate to disillusion you, but in my 7 year old son's ultra low-tech 10G
tank with one 15W fluorescent tube, Riccia is a bigger problem than algae
is in any of my bigger, better lit tanks.  Riccia does _not_ need
ultra-high light levels.

Karen