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View Full Version : LED in Algae Scrubbers do they last


Jyetman
08/21/2015, 09:36 AM
I've noticed the growth has decreased but the LED bulbs still look good. Is it just me or do these home depot LEDs need to be replaced once a year? Anyone else using LEDs?

Floyd R Turbo
08/21/2015, 06:48 PM
Which specific fixture are you using? Can you link to it? Also a pic of your scrubber would help put it into perspective, might be some other reason the scrubber growth has changed

Jyetman
08/28/2015, 10:07 AM
Which specific fixture are you using? Can you link to it? Also a pic of your scrubber would help put it into perspective, might be some other reason the scrubber growth has changed

http://www.homedepot.com/p/Cree-60W-Equivalent-Daylight-5000K-A19-Dimmable-LED-Light-Bulb-6-Pack-BA19-08050OMF-12DE26-2U100/204084368?cm_mmc=Shopping|VF&gclid=CjwKEAjwjYCvBRC99sSm_frioAwSJACrKuPC8iZ9TUJC-EDPV3yTqOipCCCfc-55CVMi7RphgyNuBBoCWdLw_wcB&gclsrc=aw.ds
I have one sided screen and two LED bulbs. This is the first bulb 60Watt Cree.

https://www.1000bulbs.com/product/118041/CREE-11027OMF2.html?utm_source=SmartFeedGoogleBase&utm_medium=Shopping&utm_term=CREE-11027OMF2&utm_content=LED+Light+Bulbs+-+75+Watt+Equal+-+2700K&utm_campaign=SmartFeedGoogleBaseShopping&gclid=CjwKEAjwjYCvBRC99sSm_frioAwSJACrKuPCo-7GGowVvLvvxYQ6u9jnK0M-MXjj94YQZplNLsU_MxoCburw_wcB
This is the second bulb 75Watt Cree.

Floyd R Turbo
08/28/2015, 01:35 PM
IMHO this type of lamp is not appropriate for algae scrubbers. This is meant to replace your desk lamps, etc. I use these everywhere in my house and they are great. But when it comes to LED lamps for an Algae Scrubber, you need to use something that has the LEDs more directly exposed to the algae. Something like a floodlight, where the LEDs are at least lined up such that their peak intensity is directed straight away from the lamp.

The Cree LED bulb and most like it do not do this: they have a cross-shaped board with LEDs on each side to achieve the most even light possible on the "bulb" part, intent being to simulate an incandescent lamp.

Also IMO it's the wrong spectrum. Ideally you want growth spectrum LEDs, which is deep red and maybe some royal blue or violet. But I have seen some Warm White LED arrays used, those are hit or miss though. It is very much dependent on you knowing exactly what the wattage of the fixtures is, and manufacturers / sellers will pump up the numbers by saying their fixture which has 18 "3W" LEDs is a 54W lamp, when it doesn't actually consume anywhere near that because they don't run the LEDs at their maximum current (because their chips are cheap and/or their heat sinks can't dissipate that much)

Home Depot makes a WW LED Spotlight that is much more intense than the "bulb", so at worst, I'd use this.

But to answer your original question: no, you don't need to change out an LED lamp nearly as often as you do a CFL. Fluorescent lamps shift color and lose intensity rather quickly so the rule of thumb is to change them out every 3 months or so.

LEDs (generally) will not shift color, and their intensity loss still happens but it's more like 7 years, or more. LEDs are usually rated by their L70 date, which is the number of hours until their output is 70% of initial. That's the 50,000 hour number. So a scrubber running LEDs 365 days/year x 18 hours/day = 6570 hours/year, then 50k/6570 = 7.6 years.

Jyetman
08/28/2015, 04:15 PM
IMHO this type of lamp is not appropriate for algae scrubbers. This is meant to replace your desk lamps, etc. I use these everywhere in my house and they are great. But when it comes to LED lamps for an Algae Scrubber, you need to use something that has the LEDs more directly exposed to the algae. Something like a floodlight, where the LEDs are at least lined up such that their peak intensity is directed straight away from the lamp.

The Cree LED bulb and most like it do not do this: they have a cross-shaped board with LEDs on each side to achieve the most even light possible on the "bulb" part, intent being to simulate an incandescent lamp.

Also IMO it's the wrong spectrum. Ideally you want growth spectrum LEDs, which is deep red and maybe some royal blue or violet. But I have seen some Warm White LED arrays used, those are hit or miss though. It is very much dependent on you knowing exactly what the wattage of the fixtures is, and manufacturers / sellers will pump up the numbers by saying their fixture which has 18 "3W" LEDs is a 54W lamp, when it doesn't actually consume anywhere near that because they don't run the LEDs at their maximum current (because their chips are cheap and/or their heat sinks can't dissipate that much)

Home Depot makes a WW LED Spotlight that is much more intense than the "bulb", so at worst, I'd use this.

But to answer your original question: no, you don't need to change out an LED lamp nearly as often as you do a CFL. Fluorescent lamps shift color and lose intensity rather quickly so the rule of thumb is to change them out every 3 months or so.

LEDs (generally) will not shift color, and their intensity loss still happens but it's more like 7 years, or more. LEDs are usually rated by their L70 date, which is the number of hours until their output is 70% of initial. That's the 50,000 hour number. So a scrubber running LEDs 365 days/year x 18 hours/day = 6570 hours/year, then 50k/6570 = 7.6 years.

Is 2700K more red then 5000k?

Floyd R Turbo
08/29/2015, 03:41 PM
generally, yes.

Jyetman
08/30/2015, 04:28 PM
generally, yes.

To give more details I'm having issues with my 5 year old 80 gallon some corals just not bright anymore, slow growth not looking healthy like they should and some smaller zoa colonies pest free partially close. Don't know if its because too little P04/NO3 or too much. I have a red sea phosphates test kit and it shows zero no color. I took water sample to LFS and they confirmed no PO4 or NO3 both zero. The scrubber screen fills with algae but some spots closes to lamp turns yellowish. The flow rate isn't consistent on my single sided 12 x 13" screen so its weak. Does this explains why I still have some algae growth in display tank if so why do the tests show zero? What test kits show actual true readings? I have 5 large fish and feed twice a day 1.5 frozen cubes so I'm introducing a decent amount of food also change 5 gallons a month.

Floyd R Turbo
08/31/2015, 08:43 AM
(edited)

Can you post some pictures and more detail of your scrubber?

12x13 = 156 sq in, 156/12 = 13 cube/day scrubber. You're feeding 1/10th of that, so your scrubber is very much oversized. This is likely the main reason you are getting the yellow growth, because the algae is trying to fill in over an area that is way too large.

The weak flow can be alleviated by downsizing your screen to more closely match what you feed. Make the screen narrower and go with the same flow, which will increase the flow rate per inch of screen. What total flow are you running at now? With a 12" wide screen, you will want 450ish GPH actual flow across the scrubber (length of slot x 35 GPH is a good number to shoot for - but can go lower)

I would recommend not going much more than 2x your feeding, which would put you at 3 cubes/day or 3x12 = 36 sq in, or 6x6. This is closer to the size that a LED floodlight would adequately cover. You might go a bit larger just in case, maybe 7x7 (49 sq in = 4 cubes/day) just because of the big fish, and the propensity to want to feed them more. But then you might have to get either a larger lamp or multiple per side (maybe make it a bit wider and shorter so you can get good coverage, like 9x5 and have 2 lamps per side, side by side)

Going by the rule of thumb for stock fixtures of 0.25W per sq in per side, that's a 9W (actual) LED lamp on each side - that's if the lamp actually pulls 9W from the wall. If in doubt, double that and go with something between 12 and 18W (actual). Then you can just play with the distance to the screen to get the right intensity and coverage - you'll have to find a "sweet spot" related to the particulars of the fixture and the system (tank) in general.

As for the test results, I haven't used RS phosphate test but my experience is that the best hobby grade tester is the Hanna Checker, either the ULN (phosphorus) or the standard phosphate checker, either of those will give you better results. I find that API is fine for Nitrates, you can see if they are rock bottom zero (bright yellow) and you can generally tell between 5-10ppm and 20ppm, other than that I use Salifert and look through the side for a low reading test.

ca1ore
08/31/2015, 10:14 AM
FWIW, I noted a material improvement in the performance of my scrubber when I switched to the red/blue LEDs. I used a pair of the ReefBreeders fuge lights (with lenses removed), but I think you can do just as well without spending that much.

Jyetman
09/02/2015, 04:35 PM
(edited)

Can you post some pictures and more detail of your scrubber?

12x13 = 156 sq in, 156/12 = 13 cube/day scrubber. You're feeding 1/10th of that, so your scrubber is very much oversized. This is likely the main reason you are getting the yellow growth, because the algae is trying to fill in over an area that is way too large.

The weak flow can be alleviated by downsizing your screen to more closely match what you feed. Make the screen narrower and go with the same flow, which will increase the flow rate per inch of screen. What total flow are you running at now? With a 12" wide screen, you will want 450ish GPH actual flow across the scrubber (length of slot x 35 GPH is a good number to shoot for - but can go lower)

I would recommend not going much more than 2x your feeding, which would put you at 3 cubes/day or 3x12 = 36 sq in, or 6x6. This is closer to the size that a LED floodlight would adequately cover. You might go a bit larger just in case, maybe 7x7 (49 sq in = 4 cubes/day) just because of the big fish, and the propensity to want to feed them more. But then you might have to get either a larger lamp or multiple per side (maybe make it a bit wider and shorter so you can get good coverage, like 9x5 and have 2 lamps per side, side by side)

Going by the rule of thumb for stock fixtures of 0.25W per sq in per side, that's a 9W (actual) LED lamp on each side - that's if the lamp actually pulls 9W from the wall. If in doubt, double that and go with something between 12 and 18W (actual). Then you can just play with the distance to the screen to get the right intensity and coverage - you'll have to find a "sweet spot" related to the particulars of the fixture and the system (tank) in general.

As for the test results, I haven't used RS phosphate test but my experience is that the best hobby grade tester is the Hanna Checker, either the ULN (phosphorus) or the standard phosphate checker, either of those will give you better results. I find that API is fine for Nitrates, you can see if they are rock bottom zero (bright yellow) and you can generally tell between 5-10ppm and 20ppm, other than that I use Salifert and look through the side for a low reading test.
Thank you for the information. I do have another question what is your thought on splitting the light cycles 6/6/6/6 or 7/5/7/5 would this provide better growth for weaker scrubbers?

imjedi76
09/02/2015, 04:47 PM
this is the guideline a lot of reefers have had success with.. also they recommend you replace bulbs every 3-4 months.

LIGHTING
-23w Spiral CFL bulbs- (2,700 kelvin is suggested)
Bulbs should be about 4 iches away from screen
Vertical MINIMUM 0.5 watts per gallon
Vertical HIGH 1.0 watts per gallon
Horizonal MINIMUM 1.5 actual watts per gallon

Floyd R Turbo
09/02/2015, 07:22 PM
Thank you for the information. I do have another question what is your thought on splitting the light cycles 6/6/6/6 or 7/5/7/5 would this provide better growth for weaker scrubbers?

This is usually only necessary until you get a base of growth started. Once you have a screen that is scrape-able, and after you scrape and rinse you still have growth in the holes, then you can switch to a single on/off photoperiod

this is the guideline a lot of reefers have had success with.. also they recommend you replace bulbs every 3-4 months.

LIGHTING
-23w Spiral CFL bulbs- (2,700 kelvin is suggested)
Bulbs should be about 4 iches away from screen
Vertical MINIMUM 0.5 watts per gallon
Vertical HIGH 1.0 watts per gallon
Horizonal MINIMUM 1.5 actual watts per gallon

That's for CFL, for LEDs it's essentially half the wattage but that has to be actual power draw from the wall, which is not necessarily the same as what the manufacturer says it is. Also you don't have to replace LEDs, a least not for 7+ years in most cases.