A well known aquarist, Bud Carlson (Turbo's Aquatics Algae Scrubbers) has been using Steve's LEDs brand drivers for a little while now. He wrote this to us, to confirm that LED drivers are a bit unique, and ours grows photosynthetic algae quite well. I'm not saying this to promote our business, but to indicate to DaveK that there is a bit of truth behind shimmer growing both algae and corals better than no shimmer. Bud is talking about growing algae scrubbers (growing algae on screens for marine aquariums, which absorb nitrates, thus lowering nitrates in aquariums in an extremely natural and non-chemical way) here, to keep it in context :
"I'm starting to see a pattern with the users of the scrubbers with the
[Steve's LEDs] driver boards, compared to the ones that use the meanwells (in
combination with the new [Steve's LEDs] LED boards)
The ones using the [Steve's LEDs] drivers seem to get initial growth really quickly.
Initial growth of algae (starting out with a plain white screen that has
never seen water) can be inhibited by too much light (too intense) so
that's why I have, in the past, included a diffuser, then with the rev 1
LED board, the jumpers, and now the dimmer option.
But going from zero to green hair algae covering the whole screen,
that's unusual. To see it happen 3 times in a week, I've never seen this.
What might explain this is flashing [ultra high frequency, not visible to human eyes]. If you research algae growth and high-frequency flashing, you will find out that a guy did an experiment
that proved that you can get the same amount of photosynthetic
production by flashing light at a high rate (in this case, it was in the
KHz range) and then varying the "on" and "off" gap. It turns out that
you can provide "light" then a "dark" period that is 10 times longer
than the "light" period, and get the same photosynthetic production as
you can with no dark period (i.e. same "light" level, all the time).
What happens is there are two "buckets" or cycles, one is a light cycle,
one a dark cycle. The light cycle fills one bucket, and then the dark
cycle "empties" that so it can be re-filled. If you just keep trying to
"fill" the "light" bucket, it can only produce so much.
This is mimicked in the ocean and pools on a sunny day when you see the
lines of really intense light dancing all around - the waves and water
surface focuses the light into very intense bursts, or "shimmer" in
tanks with metal halide lights and LEDs. This has been very much
studied with respect to coral growth in tidepools.
So my theory, at this point, is that the high-frequency flashing "seen"
by the algae is allowing this light/dark cycle to occur. The spear in
this is that once a screen gets very mature, this doesn't seem to
matter, you just blast it with full intensity. But that might be due to
the fact that water passing over the top and passing through the mat of
algae growth causes the shimmer to occur."
-Bud Carlson
Hope that helps clarify shimmer isn't really just snake oil - proof is in the pudding.
Jeff
