Algae Scrubber Basics

[Floyd R Turbo]

You're getting into questions that really need to be answered by the DIY LED guys. There are several such threads on this forum that deal with DIY LED arrays.

The reason I say that is because one thing you can do with that drivers is run parallel strings. So let's say for example each string has 10 LEDs, then then voltage drop would be around 25V, but they only need 700mA driver current. So you make 3 more strings, now you have 4 strings of 10 so you run these all in parallel, and set the drivers to 700mA x 4 = 2800mA and off you go. Basically you are building a current divider. But the catch is that each string must be electronically matched (as best as possible) to each other. LEDs change characteristics as they warm up so it is important to have them all of the same manufacturer (and a good one), same bin. Even then, you might have to mix and match to get matched strings. Then you would put a 700mA fuse on each string to make sure you didn't blow them all if one string went out. That's the basic idea but the LED gurus might have something else to say.

Alternatively you can buy 3 Meanwell LPC-35-700 drivers and put 14 660s per string for $15/ea and save yourself the hassle

http://www.rapidled.com/mean-well-lpc-35-700-constant-current-driver/

 

[mujtaba]

LED grow lights

LED grow lights

Hi, I am planning to use a grow light for my algae scrubber. The available options include either a light fixture with several low wattage LEDs (e.g 50 small LEDs in a 10watt fixture) or the ones containing 1-3 watt LEDs. Considering total wattage of the fixtures is same, what is the better option? 2ndly can u please recommend the ratio of Red and Blue leds. Most of the available fixtures have Red Blue ratio of 2:1.

 

[jedimasterben]

Thank you Floyd for steering me to constant current.

The algae filter I'm building will have 40 3W 660nm LEDs. I need to be able to dim them uniformly.

Would this driver do the trick?
http://www.ebay.com/itm/150W-Dimmab...655?pt=LH_DefaultDomain_0&hash=item3f29068c5f
This driver is adjustable from 0-4.5A. My LEDs have a forward current of 700mA. Is that current adjustable at the dimmer knob? If so, I could put a stop at 700mA.

This driver has 25-36V. My LEDs have a forward voltage of 2.5-3V. So would strings of 10 LEDs in series be the way to go?

I've been on YouTube and have been looking around and am having a heckuva time getting these basic answers. Any help would be greatly appreciated.

First and foremost, stay away from ebay for anything LED and powering them. Buy quality LEDs, you will need less of them and will know what to expect, along with using less power.

That driver you have won't work for the amount of LEDs you will be using. 2.5-3.0v is a very, very large voltage range. If you're wanting to power 40x of them from a single driver, you need a driver that outputs at least 120v. Drivers that do that are not very common and are expensive.

If you absolutely need them to be dimmable, then I would use two Inventronics 42w 700mA drivers. LED groupbuy sells them, they're $33 each. They have a voltage range from 28-56v and are dimmable via 0-10v input or a simple potentiometer.

Now, for your LEDs, if you're planning on using 40x Chinese LEDs from ebay, they probably put out maybe 350mW of light. This is an estimate based on measurements I've done from a few different sources, as the Chinese don't understand that royal blue, violet, and deep red LEDs have their radiometric output measured in milliwatts, not lumens, so just ignore any that give a reading in lumens.

Moving on, if they output 350mW apiece at 700mA, that's downright abysmal, 84 watts used to get 14 watts of output. A Luxeon Rebel deep red puts out right at double that amount, and even LED groupbuy's chips, which are more 'generic' but at least an appreciable quality, have around 560mW output at 700mA, and only use 2.6v to do it instead of '2.5-3.0v', which you should probably just assume is closer to 3v. So that's quite a bit more output with less voltage, which means less wattage is used. In addition, thanks to their much higher output, you'd only need to use 25x of those chips, so you need only two Inventronics 40w drivers and will use up ~45 watts of power. Going with Luxeon Rebels with 720mW of output and 2.3v used, you'd only need 20 of them, which means you're down to only ONE Inventronics driver and using only ~33 watts of power.


In short, buy quality. Oh, and you'll want to add a few violet LEDs into the mix, not very many.

 

[Floyd R Turbo]

Jedi, GREAT dissertation on LED quality, thank you!

Just one question though, related to that driver and my reply (and this is just a more general LED design/layout question)...that driver is 36V and 150W which means it's peak output should be about 4.1 amps total at that peak voltage and wattage. So if you were to run parallel strings (700mA per string, 4 strings, 2800mA total driver output current) then you should be able to run the full array of LEDs off of that one driver, assuming that each of the parallel strings are electronically matched and experiencing the same or very similar voltage drop, should you not?

Still, your breakdown of the driver/LED combination you laid out above makes it clear that there are likely simpler & less expensive options...I just wanted to make sure I didn't make an error in my post (2 posts above your)

 

[jedimasterben]

Jedi, GREAT dissertation on LED quality, thank you!

Just one question though, related to that driver and my reply (and this is just a more general LED design/layout question)...that driver is 36V and 150W which means it's peak output should be about 4.1 amps total at that peak voltage and wattage. So if you were to run parallel strings (700mA per string, 4 strings, 2800mA total driver output current) then you should be able to run the full array of LEDs off of that one driver, assuming that each of the parallel strings are electronically matched and experiencing the same or very similar voltage drop, should you not?

Still, your breakdown of the driver/LED combination you laid out above makes it clear that there are likely simpler & less expensive options...I just wanted to make sure I didn't make an error in my post (2 posts above your)

No, you are correct. When you split the circuit of a constant current driver, you divide the current by the number of simultaneous splits - the caveat being that the forward voltage of each string needs to be as close an exact match as possible, otherwise current will vary wildly. When running parallel, you would want to be sure to use fast-blow fuses on each string rated for the maximum current of your LEDs, and to use enough strings to reduce the current below the maximum of the LEDs so that the difference in voltage across the strings won't push current above that maximum. Generic/ebay LEDs that have large voltage ranges (like the ones above, 2.5-3.0v) will be the most susceptible to this variation in current, as there is little to no quality control to be found.

 

[Floyd R Turbo]

Hi, I am planning to use a grow light for my algae scrubber. The available options include either a light fixture with several low wattage LEDs (e.g 50 small LEDs in a 10watt fixture) or the ones containing 1-3 watt LEDs. Considering total wattage of the fixtures is same, what is the better option? 2ndly can u please recommend the ratio of Red and Blue leds. Most of the available fixtures have Red Blue ratio of 2:1.

IMO it's better to stick with the higher-power LEDs. 50 LED in a 10W fixture means that those LEDs are 0.2W each and while these seem bright to our eyes, they typically don't have much actual useable intensity for algae growth. They will definitely grow algae and this will give you the impression that they are doing the job, but when you run one of these next to a fixture with 1W or 3W chips you will see that the higher power chip fixture will grow thicker algae and sustain it longer.

Now that being said, if you have a small tank and don't need a lot of algae growth to help out your system (i.e. you are adding a scrubber as supplemental filtration, not as primary) then you *might* be able to use such a fixture on a screen match to the lamp size, but you would just have to understand that you are not likely going to be able to derive the "capacity" of your screen based on the screen size, because you are limiting it's capacity by the light fixture used. So for instance, if your fixture appears to cover a 5x5 screen rather well, and you use one on each side, normally this would be a 2 cube/day scrubber (5x5 = 25 sq in, 25/12 = 2ish) but your fixture is probably going to limit the actual capacity to 1 cube/day, or possibly less.

If you wanted to do a cheap and quick DIY and just experience how an algae scrubber works for you, this might be an OK way to start. Then if you like what you are experiencing, you could improve or rebuild it at a later date. However, you also run the risk that you will not like what you are experiencing, and that may be attributed to the poor fixture quality. So keep that in mind.

 

[Reef Junky]

one week progress

 

[Reef Junky]

 

[mujtaba]

Thanks Floyd for the advice. Can u plz also guide me regarding ideal ratio of Red and blue LEDs for Algae scrubber.

 

[Floyd R Turbo]

Not sure I can answer that precisely, but what I can tell you is that you don't need a ton of blue, just a bit, and it's not really critical, just nice to add if you can, conveniently.

Generally, I've seen the ratios of 8:1, 7:1, 6:1 thrown around. But is that a ratio of intensity, flux, etc...not sure. Probably flux. But anyways.

If you're talking LEDs, I would probably try to stick with something along the lines of the numbers above. 6 to 8 reds for every 1 blue, or equivalent. I say equivalent because I recommend using 2 blues instead of one, and running both of them at half-current. Blues are more intense and can photosaturate easily resulting in bare spots, that's why (based on experience). Run them in parallel within the series string of reds, like r-r-r-b=b-r-r-r for instance.

Running 2 blues at half-current instead of one probably will result in more blue output than running a single full-current one, but the point is to lower the peak intensity that causes photosaturation, and this method seems to work. So if you have a large array, 8:1 or even 10:1 is probably fine.

 

[Reef Junky]

when should I do my first cleaning?

 

[Floyd R Turbo]

You can clean it anywhere in the 7-14 day range, but it only needs to be a swipe of the palm and a light rinse under slow running water. Then let it grow at least 10 days. Really, until you start to get growth that is thick enough to start covering up the mesh so you can't see all of it, that's all you need to do for cleanings

 

[Reef Junky]

Good deal, I'll let it go for a while longer and clean when it thickens up more.

 

[SantaMonica]

Fun weekend reading:

Air pump recommendations for upflow scrubbers. Having bought and tried all of these, here are the best ones:


Flow (highest to lowest):

Coralife Super Luft... TONS of flow for multiple outlets or multiple scrubbers
Tetra Whisper 300... High flow if both outlets are combined into one
JW Aquatic Fusion 700... High flow if both outlets are combined into one
Tetra Whisper 150... Good flow for one outlet
Coralife Luft (regular)... Good flow for one outlet


Noise (most to least):

Coralife Super Luft... (Loud; vibrates)
Coralife Luft (regular)... (Vibrates)
JW Aquatic Fusion 700... Slight vibration
Tetra Whisper 300... Silent
Tetra Whisper 150... Silent


Size: (big to small):

Tetra Whisper 300... Large
JW Aquatic Fusion 700...Medium
Coralife Super Luft...Medium
Tetra Whisper 150...Medium
Coralife Luft (regular)... Small


Cost (most to least):

Coralife Super Luft
Coralife Luft (regular)
Tetra Whisper 300
Tetra Whisper 150
JW Aquatic Fusion 700

Overall winner for a single scrubber used at home: JW Aquatic Fusion 700 (also is the only one with adjustable flow)

Overall winner for multiple scrubbers if noise if ok: Coralife Super Luft

 

[Reef Junky]

almost two weeks. Really starting to thicken up.

 

[Reef Junky]

Well I now have green thick algae covering the sheet. Have not noticed any difference in the tanks algae or params. Hopefully now that the algae on the mesh looks like it's really going good I'll see results in the next month.

Have you heard of the water yellowing because of the use of ats? Hesrd this the other day from a local and curious if anyone has had this happen to them?

 

[Floyd R Turbo]

That's what happened back 20 yrs ago when you run a horizontal screen and didn't remove it while cleaning. Removing the screen and cleaning/rinsing in the sink means no yellow water.

 

[SantaMonica]

Yellowing is cause by letting it get too thick, and the underlying layers die and turn into "wheat" which looks tan/brown.

 

[Bignose94015]

Hello all. I am new to UAS and built a floating scrubber. It looks similar to the SURF 2 and I am utilizing 5 red LEDS. I have been running it now for about 8 days and only am getting what I believe to by Cyno in the scrubber. It is dark brown/black and really goey like snot. There are also some small patches of almost clear algae that are also the consistency of snot. I am currently running my lights for 18 hours with no cloth. My total volume in tank is about 105 gallons with two clown fish only at this time so feeding is very light. I had a huge outbreak of Cyno in the DT which is well on its way to being gone. Any ideas on how to get my ATS growing green stuff?

Thank you,

Eric

 

[jedimasterben]

Hello all. I am new to UAS and built a floating scrubber. It looks similar to the SURF 2 and I am utilizing 5 red LEDS. I have been running it now for about 8 days and only am getting what I believe to by Cyno in the scrubber. It is dark brown/black and really goey like snot. There are also some small patches of almost clear algae that are also the consistency of snot. I am currently running my lights for 18 hours with no cloth. My total volume in tank is about 105 gallons with two clown fish only at this time so feeding is very light. I had a huge outbreak of Cyno in the DT which is well on its way to being gone. Any ideas on how to get my ATS growing green stuff?

Thank you,

Eric

How big is it and how spread out is the light? If you're running the red LEDs (I hope you mean deep red) at full current and they're only a couple of inches away, you're probably overlighting it by a significant amount and the algae just can't take hold there.