- Today on BRSTV Investigates,
how much sand do you really need for a one inch sand bed
and are the sand bed calculators close?
(driving music)
Hi, I'm Randy with this Friday's BRSTV Investigates,
where we put popular reefing gear, theories,
and methods to the test by experimenting
on our own tanks so you don't have to experiment on yours.
In today's experiment we take our five most popular
sand substrates, both dry and wet, and find out
how much is needed to create a one inch sand bed
per square foot in order to test the question
"Are online sand bed calculators reliable?"
Let's find out.
In the last episode we tested how much sand you really got,
whether you bought 40 pounds of dry
or 40 pounds of wet sand
and today we're taking that one step further
to help you decide how much sand you need
for your tank in the first place.
Which, for me, is important in two ways.
One, so I can plan out my tank costs
before spending the money.
And two, so I can get the right amount of sand
at once rather than multiple trips and purchases.
With that in mind, there are several sand bed calculators
out there that will do this math for you,
but how reliable are they
and is one more accurate than the other?
Here's how we approached today's sand bed depth test.
In order to test this one,
we took a Mister Aqua 12 by 12 inch,
seven and a half gallon cube tank
and marked it at one inch above the bottom of the tank
on all four sides.
We then took our five most popular sand substrates
with the wet and dry versions of CaribSea's Special Grade
and Fiji Pink sands, as well as
the CaribSea Bahama Oolite sand
and then leveled out each one into a one inch sand bed
in our testing cube tank.
After weighing each one and accounting
for the dry tank weight, we developed an idea
of how many pounds of sand per square foot
you would need.
In order to compare our results against
the sand bed calculator, we searched for
the most comprehensive calculator we could find,
which offered more than just approximate
pounds per cubic foot sand grain weight
and found this calculator from aqua-calc.com
that has nearly every available type of CaribSea sand listed
along with its weight in grams per cubic centimeter.
So with that, here's what we found.
For today's results, we'll first look at
the online sand bed calculator result
for that type of sand, at one inch,
and then compare that to what we found in the testing lab.
I will note that we aren't looking for exact numbers here
and weights, because it's pretty unreasonable
to think about precision when talking
about single grains of sand.
However, a difference of a few to five to 10 pounds
to create your ideal sand bed may mean
anywhere from 12 to 24 bucks worth of additional sand
that you might have to pick up to get there.
Getting started with the CaribSea Special Grade
Arag-Alive wet sand for a one inch sand bed
in a square foot, the calculator states that we would need
about seven point zero eight pounds.
When I tested in the lab using a freshly opened bag
of damp Special Grade sand, I find that it took
seven point one three pounds to create
our one inch sand bed.
So nearly exactly what the calculator recommended.
However in our last test, we found that there was
a little over 20% less sand in wet bags versus dry,
so in this case, while the calculator was right
against the weight of a brand new bag of wet sand,
we can't expect to accurately use the calculator
to buy the right amount of sand unless you factor in
about 20% more for water weight.
Next up is the Special Grade Dry Sand,
which the online calculator lists as the same grams
per cubic centimeter as the Special Grade Wet,
meaning that again we would need
seven point zero eight pounds to make our one inch sand bed.
However when I tested, I found that it took
six point seven nine pounds.
Again, not exact, but pretty darn close.
And in this case, water isn't a factor,
so I'd feel confident using the calculator's recommendation.
For the Fiji Pink Wet Sand and Dry Sand,
again the calculator lists both as needing
seven and a half pounds to make a one inch sand bed
per square foot.
And in our testing we found that the wet bag
of Fiji Pink sand also has about 20% less sand
than a dry bag, in which case the calculator was very close
to what we measured for wet Fiji Pink,
coming in at seven point six five pounds.
But, again, I'd feel more confident if I factored out
the water and went with a higher amount
per square foot.
The dry Fiji Pink, however, was a pound under
the calculator recommendation of seven and a half pounds,
where it only took us six point five three pounds
to make one inches deep.
I would say that this isn't a game changer difference,
but the finer grains do require slightly more
than larger grains and should be a consideration
for larger tanks with higher square footage to cover.
We also tested out fifth most popular CaribSea sand
with the wet Bahama Oolite fine grain sand,
which is one of the finest sands listed
in the online calculator at one point five four grams
per cubic centimeter, which calculated out
to needing eight pounds exactly to create
a one inch sand bed per square foot area.
However in our lab testing we found that it took
ten point eight seven pounds to create
that one inch sand bed.
So it is a little over two and a half pound difference,
but a very fine grain of this type of sand
lends itself to retaining more water
than the larger sand grain types
and if we took the time to allow it
to completely dry out, I would expect these numbers
to be very similar, if not the same,
which is why I'm rating today's question of
"Are online sand bed calculators reliable?"
a six out of 10 on the reef certainty scale.
The calculator is accurate enough
to the number of pounds of sand, but I'd say
it lacks a bit in accounting for what's actually
in the bag, so at best, if I were calculating wet sand
for my own tank, I'd increase
the calculator's recommendation by 20% to be safe.
After finding this online calculator from aqua-calc.com
that takes the guesswork out of how much the sand weighs
by including the most popular options in there.
I wouldn't hesitate to use this calculator or one like it
when planning out my next sand bed.
As well as using this live sand and wet sand playlist
over here to find out how to add sand to your
bare-bottomed tank or which goes first, sand or rock.