White acrylic will let some light through
Not acrylic; a white coating on the black acrylic.
Where do I get crushed Quartz for a small UAS? Or is there something else I should use and is easier/cheaper to find?
Fine gravel is good and easy for most people; just not as bright.
how many CFL bulbs per side? How many LEDs? Screen is about 12x8
Here is a guide;
Scrubbers are sized according to feeding. Nutrients "in" (feeding) must equal nutrients "out" (scrubber growth), no matter how many gallons or liters you have. (However each 50 pounds of problem rock adds 1 cube a day)
So...
An example VERTICAL upflow or waterfall screen size is 3 X 4 inches = 12 square inches of screen (7.5 X 10 cm = 75 sq cm) with a total of 12 real watts (not equivalent) of fluorescent light for 18 hours a day. If all 12 watts are on one side, it is a 1-sided screen. If 6 watts are on each side, it is a 2-sided screen, but the total is still 12 watts for 18 hours a day. This screen size and wattage should be able to handle the following amounts of daily feeding:
1 frozen cube per day (2-sided screen), or
1/2 frozen cube per day (1-sided screen), or
10 pinches of flake food per day (2-sided screen), or
5 pinches of flake food per day (1-sided screen), or
10 square inches (60 sq cm) of nori per day (2-sided screen), or
5 square inches (30 sq cm) of nori per day (1-sided screen), or
0.1 dry ounce (2.8 grams) of pellet food per day (2-sided screen), or
0.05 dry ounce (1.4 grams) of pellet food per day (1-sided screen)
High-wattage technique: Double the wattage, and cut the hours in half (to 9 per day). This will get brown screens to grow green much faster. Thus the example above would be 12 watts on each side, for a total of 24 watts, but for only 9 hours per day. If growth starts to turn YELLOW, then increase the flow, or add iron, or reduce the number of hours. And since the bulbs are operating for 9 hours instead of 18, they will last 6 months instead of 3 months.
HORIZONTAL screens: Multiply the screen size by 4, and the wattage by 1 1/2. Flow is 24 hours, and is at least 35 gph per inch of width of screen [60 lph per cm], EVEN IF one sided or horizontal.
FLOATING SURFACE SCRUBBERS WITH RIBBONS: Screen size is the size of the box (Lenth X Width), and is 2-sided because the ribbons grow in 3D.
LEDs: Use half the wattage as above. 660nm (red) is best. You can mix in a little 450nm (blue) if you want.
Very rough screen made of roughed-up-like-a-cactus plastic canvas, unless floating surface, which would use gravel and strings instead.
Clean algae:
Every 7 to 21 days, or
When it's black, or
When it fills up, or
When algae lets go, or
When nutrients start to rise