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- It's BRStv Reef Fact Wednesday
and today we answer how many of
these modules do we really need,
and how do ya space them?
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Hey, I'm Ryan with BRStv Reef Facts.
Where every week we do our best to help you guys
enjoy your tanks and find new ways to explore the hobby.
We do that with quick, straight to
the point answers to your questions.
Today is all about how many of these modules
are required for your tank and how to space them.
Somethin' that when you're done with this video,
you can be confident about.
I'll be frank, the manufacturers don't
make it super clear what you should pick up
and how to space them because it's generally based
on one very specific generic tank.
That's not very helpful to most of us,
so let's take it one step further.
We're gonna split that up into two
very distinct guidance paths for both
SPS acropora dominant tank and then everything else.
Everything else being your LPS, softy,
polyp, and similar tanks.
I'd say 90 percent of you fall
into one of those two categories.
Let's start with LPS, softy, polyp, and similar tanks.
This also includes mixed tanks
which only have a few SPS corrals.
These types of tanks are just a
lot easier to light or get right.
What most of the general recommendations
the manufacturers are giving are based on.
We can't cover every last brand out there,
but I actually think that's actually
unnecessary in most cases.
Most of the popular LD modules can
actually be broken up into wattage groupings.
For your average two foot tall and deep tanks,
90 watt LED modules seem to be the sweet spot
with the intersection of coverage,
intensity, reasonable mounting heights
and cost seem to intersect.
For your average LPS, softy, polyp, and similar tanks,
this also includes those mixed tanks
which only have a few SPS corrals,
there's really no need to go much
higher than a 90 watt module as well.
These 90 watt options make up a majority
of what people are picking up from us,
and it actually falls out pretty rapidly after that.
In fact, I'll share them in that order.
With the Kessil 360X, Radion XR15 with diffuser,
and AI Hydra 26.
With all of these approximately 90 watt lights
and this tank type, they should all cover
a two foot by two foot area so a single module in a 60 cube,
two modules in a 120 gallon tank,
and three of them in a six foot 180 gallon tank.
If you have a tank which is less deep front to back,
like a 90 gallon tank which is only 18 inches front to back,
I think I'd still consider one 90 watt module
per 24 inches left to right and use two modules.
Now none of that is ground breaking in the LPS
and similar tank types are just not super hard to get right.
They're just that susceptible to shadowing issues.
Because the lights are not overpowered,
hot spots are less of an issue and in fact,
with those tank types too much light
from LEDs is often the biggest issue.
It's just pretty easy to get right,
and one 90 watt light per 24 inches of width
will probably get you where you need to go.
So we're gonna move on to those SPS dominant,
specifically acropora dominant tanks.
The challenges here are just significantly different.
I'd say there are three challenges almost
every SPS reefer will agree with.
First, shadowing becomes a major issue
with branching acropora specifically as the corral grows,
it shadows its neighbors then shadows its own base,
as well as its own internal branches.
This shadowing causes undesirable growth patterns,
brown out of the internal tissue, clearly dead bases,
and all kinds of things that you don't
want to see in an SPS dominant tank.
Second, par hot spots become a bigger issue.
Acro or SPS dominant tanks require intense light.
The solid reliable goal for an SPS tank
is 250 in as much of the tank as possible,
knowing you'll always be brighter or darker in some areas.
Another way to think of that issue
for 200 to 300 par in as mush as the tank as possible,
a range that we saw super effective
in the WWC 900 when we tested it.
If you achieve that range, you can be sure
that neither par or intensity will
ever be an issue in your tank.
The challenge here is if we approach it
the same way with one light every 24 inches,
we have to use much stronger light
sources like the Hydro 52 or XR30.
That can work, but the reality is the brighter the light
they'll likely be 500 to 600 par to
achieve 250 12 inches to the right or 18 inches down.
So you get pretty significant hot spots and shadows
with spacing 24 inches in very intense light sources.
The third challenge is what I'd call spectrum hot spots,
meaning all of those LED modules need to
affective blend all of the individual
LED colors into one cohesive spectrum.
If they don't, the corrals will get hit
with peaks and valleys of specific spectrums
with really unknown effects.
SPS corrals in particular seem to have
pretty drastic color change and
health responses to different spectrum bulbs,
so we know this is important to their biology
they're just challenges to doing this perfectly
eight inches from the water's surface.
Particularly when the channels are all cranked to the max,
they're just very likely spectrum hot spots
and deficiencies in the top third of the tank.
Okay, so what are the solutions to all that
and what is the proper spacing for an acro tank like this?
Well the first and probably cheapest
is actually just to keep your 24 inch spacing
and 90 watt modules but then add in some T5 for fill light.
This will eliminate your shadow issue
and add the required intensity with much more
muted par hot spots and then the evenly
blended spectrum form the T5 lamps will
also mute the effect of spectrum hot spots as well.
That said, if you're watching this you
probably wanna know how to do this with
LEDs alone and there are three really easy options.
First you can simply get the high powered options
like the XR30 and then raise them up pretty high,
like 12 to 18 inches off the surface
of the tank like WWC does and then we did with the XXL750.
Raising lights up helps with shadows,
even intensity and spectrum blending.
It all gets significantly better performance
with every single inch you raise the lights.
The challenge here is, is you get a lot of spill
into the room that can not only be visually undesirable,
but also a waste of energy and to some degree
a waste of an expensive light's performance.
Second option is simply space the more
moderately powered LEDs closer together
and create more intersecting sources of light.
Essentially replacing higher powered spot lights
with a grid of moderately powered intersecting lights.
The good news is four XR15s is about the same price
as two XR30s so its not really a price consideration,
and I think basically every successful
SPS reefer will tell you four single puck XR15s
spaced evenly will perform better than two XR30s
on a standard size or shaped tank.
Same with evenly spaced Kessil 360Xs and Hydro 26s.
So with all of these 90 watt modules I suggest
one every 18 inches left to right for good performance,
and one every 12 inches from left to right
for the best performance.
And what I'd call a nearly ideal blanked of light solution,
which we implemented on the XXL750,
we actually did one every 14 inches but in two rows,
which probably overkill on a 24 inch
deep tank front to back,
but ideal for those 30 to 36 inch deep tanks front to back.
Related to that multiple row and even coverage idea
on a more common sized tank with a four foot 120,
one of the best options we actually tested
was a grid of six to eight AI Primes.
This is actually close to the same
or less cost than two of the highest powered options,
again the conversation not necessarily about cost,
just selection about the right tool for the right job
and getting the best results, sometimes it's even cheaper.
The third option is actually look at
the LED options which come in a large
grid form factor out of the box.
The most common option is Orphek Atlantic.
This is visually obvious grid of intersecting LEDs
that create a blanket of light
and it's easy to understand why their
shadowing won't be an issue,
hot spots won't be an issue,
and the light is designed to be mounted high
so spectrum blending is less of an issue as well.
On a standard 24 inch deep tank front to back,
I'd say that a single 210 Orphek Atlantic
will be enough for a 48 inch LSP tank.
A single 210 watt Orphek Atlantic will cover
a 36 inch SPS tank as well as two on a six foot 180,
but they can actually be mounted end to end
like two on a 120 if overkill's your goal.
Even thought the unit itself is more expensive,
it can be about the same price of other options
when you consider the ideal 36 inch performance.
All this should shed some light on how
simple lighting selection and spacing is
for an LPS and similar tanks as well as
challenges and direct solutions
with most SPS tanks, specifically acro tanks.
As always, the proof is in the data so
I put together a special playlist with
all of our Investigates episodes and the individual lights.
You can see the par distribution of
all kinds of different configurations
with the most popular lights out there.
You can also find all the lighting
videos in a category on our website.
So see you next Wednesday for the
next batch of BRStv Reef Facts.
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