Algae Scrubber Basics

[zemuss]

Floyd,

I currently have my Algae Scrubber setup with this LED: Shop Utilitech 13.5-Watt (60 W) Warm White (3000 K) Decorative LED Bulb ENERGY STAR at Lowes.comt appears to be working but slower growth right now as the algae is seeding on the mesh surface ,but I can tell you it has only been one week. I will post pictures after about a month of use. My goal is to eliminate the nutrients with the scrubber and hope it works.

Future design will be to use all red LEDs. Most Likely 4 LEDS on a single side of the mat, not a dual light system but have thought about it.

"Z"

 

[zemuss]

Also wanted to note that the bulb has a difuser and I spread the light source with a reflector I purchased from Lowes. The reflector is a typical hanging or clip on reflector. It does the job I think.

 

[SeymourDuncan]

Welcome and thanks! You are now a member of one of the most open minded family oriented forums on the planet!!! Literally any idea from smart to insane is treated equally here, no judging and the only fires we light are on our grills

 

[Codemonkey812]

I have had a algae scrubber for about an year. I am still not getting proper growth. Any input?

. I have two 90watt CFL floods on it for 15 hours.

 

[Turbo's Aquatics]

Floyd,

I currently have my Algae Scrubber setup with this LED: Shop Utilitech 13.5-Watt (60 W) Warm White (3000 K) Decorative LED Bulb ENERGY STAR at Lowes.comt appears to be working but slower growth right now as the algae is seeding on the mesh surface ,but I can tell you it has only been one week. I will post pictures after about a month of use. My goal is to eliminate the nutrients with the scrubber and hope it works.

Future design will be to use all red LEDs. Most Likely 4 LEDS on a single side of the mat, not a dual light system but have thought about it.

Warm White LEDs won't work well, even less when they are store-bought home use lamps. LEDs and CFLs are physically different sources and do not translate. You would be better off with CFLs in reflectors or just CFL floodlights until you build a 660nm Deep Red LED array.

LED spectra are element based, and while there can be a fair spread of spectrum on a chart, mostly algae only need the deep red spectrum. Fluorescent sources are phosphor based, the light is inherently UV (UV fluorescent tubes just have no phosphor coating) and the combination of different phosphors results in the desired spectrum.

"Z"

I have had a algae scrubber for about an year. I am still not getting proper growth. Any input?

. I have two 90watt CFL floods on it for 15 hours.

"proper", IMO, is growth that reduces nutrients and combats display algae. With that said, how are your water parameters and how does your tank look?

Just a few things I notice from the pic though

- you have floodlight CFLs which don't require a reflector (so you can take them out in case you need to make some space)
- you have a mixture of growth in patterns, looks like no growth in the middle, then yellow spongy growth, then dark brown. Am I seeing this right?

A few ?s

how much do you feed?
Tank size?
Livestock?
Measured flow across screen?
When did you change the lamps last?

Let me know and I'll see if I can spot anything....

 

[SeymourDuncan]

Here's my experiment with a somewhat different style algae scrubber.
Its more a bacteria scrubber than anything, as i have not had a hair algae problem so I designed this to combat cyano, its certainly working! We had a tornado rip through today (missed me) so ill update the progress tomorrow
https://www.reef2reef.com/forums/showthread.php?t=124445

 

[Browncoat]

Amazing thread! Thanks for all the info here. Algae scrubber is without a doubt one of the best things I've added to help filtration and combat algae on the DT!

 

[Codemonkey812]

"proper", IMO, is growth that reduces nutrients and combats display algae. With that said, how are your water parameters and how does your tank look? -- The rock and sand look good, it's just the glass needs cleaned every couple of days.

Just a few things I notice from the pic though

- you have floodlight CFLs which don't require a reflector (so you can take them out in case you need to make some space)
- you have a mixture of growth in patterns, looks like no growth in the middle, then yellow spongy growth, then dark brown. Am I seeing this right? -- That is correct, I am not getting green turf algae like I would like.

A few ?s

how much do you feed? -- About one ounce of frozen food daily, and one sheet of algae every other day.
Tank size? -- 75g with 20g sump
Livestock? -- I am heavy on the live stock (flame angel, Dispar Anthias, Ocellaris Clown, Yellow Tail Blue Damsel, Mandarin, Purple Firefish, Yellow Watchman Goby, Foxface, Hippo Tang, Blue Tuxedo Urchin)
Measured flow across screen? I need to check this
When did you change the lamps last? They are about 7 or 8 months old.

Let me know and I'll see if I can spot anything....

 

[Turbo's Aquatics]

Fluorescent lamps need to be changed every 3 months, so that could be one problem

I forgot to ask, what spectrum are they?

CFL floods are good for about a 6x6 area right in front of the lamp when placed at about 4" away. If you want to cover a larger screen, you would want to use spiral CFLs and a large dome reflector. Otherwise you will tend to get what you have, which is a hotspot in the middle (no growth) and then growth that changes radially outward. The yellow you are getting is too much light compared to the nutrients, then the dark growth is too much nutrients compared to the light.

I would

1) increase flow, I'm guessing it's low, but first check #2 below
2) make sure your slot pipe is cut even and straight. A long slot will tend to pinch closed in the middle after you cut it all the way, the pipe wants to close - so you have to go back over it again in the middle. I cut mine using a jig and a router and I make 2 passes, but that's me. I'm anal.
3) If you want to continue to use CFL floods, use 2 smaller wattage ones on each side and put them 4" away, side-by-side. If you want to use one, go spiral and dome reflector. The point is even coverage.
4) make sure they are 2700-3000K
5) screen does seem a little large for the load, but you are only getting growth on glass so that it a good sign, why fix it if it ain't broke. Just tweak it per 1-4 above

 

[zemuss]

Update on my scrubber. I actually went back to a cfm bulb because the LED lamp was overheating to the point it burnt my fingers last night. Not a bad burn just enough to notice I should rethink the plan. So I am using a 3500k for now and will see about getting my LED Reds soon.

 

[Turbo's Aquatics]

Sounds like your heat sink was inadequate. All my heat sinks are cool enough to hold me hand on them indefinitely

 

[zemuss]

It was the heat sink that came with the bulb. I am going to be moving to a different setup but for now the CFM bulb will serve its purpose.

 

[zemuss]

So I replaced the LED bulb with the CFM bulb and wow did the algae take off. I need to post pictures but its been a week and the algae on the screen is amazing. For now I will stick with the cfm bulb with no plans of upgrading the lights.

I will be doing some modifications in the upcoming future because the screen is too short which causes a stream of water to run out the front and back. So I need to cut another pvc to the length of the screen.

 

[Turbo's Aquatics]

Can you post a link to the LED bulb you were using?

Do you mean CFL? Compact Fluorescent Lamp?

 

[dbg]

Following... this is awesome! =)

 

[SantaMonica]

Here is an update on scrubber sizing:

Scrubbers are sized according to feeding. Nutrients "in" (feeding) must equal nutrients "out" (scrubber growth), no matter how many gallons or liters you have. 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

 

[Bad Company]

Floyd or Santa,
What are your thoughts on using Ecoxotic stunner strips as lighting for a scrubber? I have a few extra of the 6w 12.5" 8500k whites and the 450nm royal blues. I know they don't have much red in them. Whould they work?

Thanks!

 

[Turbo's Aquatics]

LEDs need to be 660nm Deep Red, I prefer Philips Luxeon ES from Steve's LEDs myself. 8500K is the wrong color temp in any case. I have seen people use the red stunner strips but I don't know how effective they are.

As far as LED arrays go, the guideline that I have been recommending has been based on coverage rather than wattage, as this is rather confusing (because 3W Deep Reds are 700mA max current @ 2.2Vdrop = 1.5W actual consumption, etc)

Anyways....

Minimum coverage for LEDs: one 3W 660nw Deep Red LED on each side of every 8 sq in of screen.
Maximum coverage for LEDs: one 3W 660nw Deep Red LED on each side of every 4 sq in of screen.

So for instance if you built a 4 cube/day scrubber, which would be 48 sq in, then you would wand a minimum of 6 LEDs on each side, and a maximum of 12 on each side.

Additionally, what I have found is that if you run the LEDs at full power (700mA drive current) on a brand new screen, it will tend to photosaturate the screen and it can take longer to get through the initial curing/maturing stage. This is especially the case when running maximum coverage (one on each side of every 4 sq in). So either 1) you must place a diffuser in front of the array (prismatic diffuser from Lowe's, Plaskolite, green label) or you can run the array at 350mA by paralleling the arrays. Then, when the screen is mature (holes are filled in and don't detach when scraping) you can remove the diffuser or flip the parallel connection to series and go to full drive current. Alternatively, you can use a high coverage array and split the photoperiod up into several throughout the day. The issue comes down to too much light available and not enough algae to absorb it all, so my theory is that what is there tries to absorb it (or has no choice) and growth stops. This is true for all scrubbers.

LEDs penetrate through the growth much better than CFL or T5HO. So this has the dual effect of letting you go longer in your growth cycle for better filtering, but the downside is you can photo saturate your screen easier. So you cannot follow the "18 hrs on 6 hrs off" rule that was set in place for fluorescent sources, at least not initially. If you use the minimal coverage, you can run the array a bit longer usually. For the high coverage though, you can easily photoinhibit the growth with a long photoperiod.

All of this being said, there is no "double the light/wattage" rule that applies for single-sided screens running LEDs. The maximum coverage is the maximum coverage. Any more that one 3W 660nm Deep Red per 4 sq in of screen on each side (or one side) will likely result in quicker photoinhibition.

Regarding supplementation with blue: this needs to be done very conservatively. Not much is needed. I use 2 3W 440-445nm Blues for every 6 660nm Deep Reds and I put them in the center of the 2x2 'square' of blues, then I wire 2 of the + and - terminals together so that they run in parallel (i.e. current divider/half power) on the same string as the reds (700mA driver, so 350mA current). 3W blues at 700mA will photoinhibit, even on a very mature screen (you will have a bare white spot on the screen in front of it). 1W blues could be used to avoid having to wire in parallel. But the point is that blue use does not need to be very much at all - just enough to hit the spectrum with minimal intensity.

From what I've seen, blue supplementation does not promote drastically more growth, but it does seem to "bolster" what growth you have - it gets tougher to scrape. I would deem it nice to have, but not necessary, not absolutely.

 

[bmeudy]

Quick question. If I'm using 660nm Deep Red Leds in my DT (4 total over 90 gallon), will this accelerate algae growth in my dt?

 

[Turbo's Aquatics]

IMO, no. At that level it's really only supplemental red, and I won't get into the argument for or against that, except to say that all you probably need is 350mA current on those at best. If you have proper filtration in place, maintain stable parameters (alk cal mag sal temp, etc) for long term, and maintain a consistent husbandry/maintenance schedule, these is the bigger factors in keeping DT algae under control.