Coral T5 vs LED Light

Experimenting With the Star Polyp

10-25-09 Setting Up the Tanks
"Well, after many weeks of cutting pvc and going in early every morning for about a month, I finally have put together the
three 20 gallon tanks into a working system to test the LEDs against a control and it doesn't leak! I have attached a few
pictures to give you an idea of the setting of the tanks and where I will be testing, and the whole science department is
pretty interested, as there have not been many active experiments conducted in school for a while. This week I will be
taking pictures as I start to put rock and sand in the tanks, preparing it for coral. I was able to find pvc after a while, but
did cost a bit, but its finally ready. In a week or so I should have a few fragments of star polyp that I propagated from a
mother colony I grew at home to make sure the tank is safe, and then I would want to move on to higher light needs coral.
However, I am not sure where I will get them yet, but hopefully I should find them soon. Other than coral, the control light I
have on the tank right now is pretty weak, and will limit me to low light corals for experimentation, so eventually I should
find a stronger one." Matt G.

12-10-09
"I wanted to give you an update on how the corals have been growing under the LED light compared to the T5
control, as well as show you the pictures that accompany the trends I am seeing.
One that I find interesting is that all the corals that are under the LEDs are significantly taller and slender, as they
are reaching up towards the light much more than the control. I have pictures to show this, and many may say this
means they are reaching towards the light because they need more. However, the corals under the LEDs seem to
be growing at a slightly faster rate than the control and have a nicer appearance to people who have viewed the
project. Also, to possibly counteract the possibility that the corals are reaching towards the light because they
don't have enough light, but because they like it, could possibly be supported by the fact that a certain coral, Pink
Anthelia, that is in all three tanks has grown the tallest in the pure LED tank, then in the diffused LED tank it is
shorter, but still taller than the Control. If the lights were too weak, wouldn't it be logical to assume that the
diffused LED coral would grow taller than the one with only LEDs as the diffused bars are giving off less light than
the bars by themselves? Also, it has been four weeks and if light was an issue for these fairy low light needs
corals, they would have died by now (however, newer hard corals may set this distinction depending if they live or
not when I can find specimens). I am going to make a few more cuttings of the Anthelia to test to make sure this
trend is seen consistently, but it definitely is interesting. Also, other anemones that are mobile are going as close
to the LEDs as possible with tall bodies, while the control Anemones display a tendency to be short and stout at
the bottom regions of the tank. Once again, either they need more light or they like it, but the anemones do look
slightly better in the control tank.
Also, a mushroom coral (usually fairly immobile) in the LED tank has actually began to migrate closer to the light,
and has had a tendency ever since the beginning of the experiment to reach up towards the LEDs while the
control mushroom coral has stayed down and flat against the rock it is attached to. Also, the red coralline algae
that was seen that I saw growing at faster rates in my 70 gallon tank in the first bit of testing is appearing in all the
tanks and I will monitor it, but it seems that the LEDs produce far less diatoms than the control tank, as the control
needs to be clean almost twice a day from the brown muck they create while the two LED tanks can go for weeks
at a time without the glass being cleaned and still have very little brown diatom build-up comparably to the side of
the tanks." Matt G.