Re: Light and traces

[Thomas Barr <tcbiii at earthlink_net>]

> Tom wrote:
> 
> I have 20 gallon tanks with 110 watts sitting on them algae free for
> many
> years. The better the filter, the less chance of GW.
> 
> - ------------------------------------------------------------------------
> - --------
> 
> Which type of light do you have on that 20 gallon tank? Is it the
> triphosphor lamp or the full spectrum lamp?

6700K for a awhile(4years one tank), switched some to 5000K + 6700 mix.

> I am curious because I am
> wondering if tri-phosphor lamps are able to destabilize the chelator in
> TMG. It sure appears to me that when I use triphosphor lamps I have to
> constantly add trace elements way out of proportion to the light level.

Well at nice lighting color temps and good plant growth I can see why:)
Do you get more growth? Do the plants look better? What exactly are you
comparing this too? New tri phosphors vs something that's been hanging out
for 1-2 years? PC's vs NO FL's? Just one tank or several? One type of tap
water etc...
Comparative studies(or hokey hobbyist experiments even) can say more about
these types of problems.
It's hard to see the other possibilities or things that might be influencing
what you are seeing. Harder tap waters seem to use/need more traces etc than
soft water.  

> I have noticed that other people have to add large amounts of trace with
> those 96 watt fixtures. Maybe Roxanne is just not able to keep up with
> the trace elements.

This is simply a function of increased plant growth, not light breaking down
the chelator from what I can gauge. Try SeaChem's flourish iron which uses
gluconate instead. I think you will see little differences between the two.
The light etc might break down a small amount of iron etc but not much would
be my guess. 

Of course I add loads of traces anyway, some folks skirt the lower leaner
limits with their trace additions. But I've let things run fairly lean and
never saw any thing I'd consider from this or or UV which would have a high
and better chance at breaking the chelator down.

You also need to consider the time scales here. The traces are sucked up etc
and out of the water column(Fe at least) pretty quick. Dupla has those daily
drops etc. I think there's not enough time for the lights to do this, the
iron is complexed, taken up, precipitated etc. Who quite knows where it all
goes? Well, I'll focus just on bio uptake. It just seems like from what I've
seen, not much differences between the two above sources of iron.
In the lower lighting(say 1.6 watt of NO FL's), I had nice growth etc at the
same levels but uptake was slower. Good healthy slower growth= slower
uptake. Faster healthy growth w/higher lighting= faster uptake. Traces,
macros, CO2 etc. 
Things have their usable limits though......plants can have only a set max
growth rate. Which is a good thing considering Kudzu:-)

Regards, 
Tom Barr  
  
 
> 
> Wayne