Algae Scrubber Advanced

[Floyd R Turbo]

Yes, you have it backwards. 2700-3000K for T5HO and CFL. 630/660nm red with maybe 425/455 blue in a 7 red to 1 blue ratio (blue is optional) for LED.

 

[N728NY]

Your recommending 0.5 watts of LEDs per gallon. Would you mind converting that to mcd per gallon. I am looking at 2 LEDs:
1600 mcd / (1.85 V * 0.2 a) = 4,324 mcd / watt
2800 mcd / (1.7 V * 0.3a) = 5,490 mcd / watt
You will not neither of these are 1 watt . But one produces 25% more light. Don't you love the LED efficiency it makes picking the right one that much harder

This would be a more solid scientific thing to go by if you could either get a specific lumen or candela power that you need for the screens then you could easily run with that and convert that to any type of lighting that you desire to use (LED, CFL, Incondescent). Being wattage is only a measure of power which I am almost sure you will find that different brands of LEDs are going to have different mcds per watt (as it looks like FishMan may have discovered). Hope this helps a little, I'm an electrician so trying to throw what little knowledge I have about lighting. Maybe we could go back and see what cfl's worked best, see what the candela output was for that bulb, and then we could easily add as many LEDs we need to produce the same candela power?

 

[N728NY]

Holy Cow!!! I just replaced my cfls with a high kelvin rating! Going to definitely fix that tomorrow!! Maybe that's why I haven't seen a lot of growth! Thanks a ton!

 

[N728NY]

Holy Cow!!! I just replaced my cfls with a high kelvin rating! Going to definitely fix that tomorrow!! Maybe that's why I haven't seen a lot of growth! Thanks a ton!

LOL I just replaced them! Swapped some bulbs out from around the house. Wife won't be too happy. She hates the higher kelvin bulbs. She'll be happier when I tell her it was for the survival of the tank! How about wattage? I been using 13watt cfls (equivalent 60w incondescent). Have I at least been right on them?

 

[TheFishMan65]

I found a chart online; great reference if it is correct (I have no reason not to believe it)
13 watt CFL produces 850 lumen
18 watt CFl produces 1100 lumen
23 watt CFL produces 1600
Based on this run a 23, 13 then 18 for efficiency of lumens per watt. So at 1 watt per gallon that is somewhere between 61 and 69 lumens per gallon.
Now the problem with low power LEDs is that they are listed in MCD which apparently does not have a direct ratio to Lumens, but let me go see what I can find.

 

[der_wille_zur_macht]

Your recommending 0.5 watts of LEDs per gallon. Would you mind converting that to mcd per gallon. I am looking at 2 LEDs:
1600 mcd / (1.85 V * 0.2 a) = 4,324 mcd / watt
2800 mcd / (1.7 V * 0.3a) = 5,490 mcd / watt
You will not neither of these are 1 watt . But one produces 25% more light. Don't you love the LED efficiency it makes picking the right one that much harder

Can you link to these LEDs?

There are a few HP LEDs out there that I was looking at but these sound like old fashioned low power LEDs. Would be interesting to compare efficiency, and also distribution, as some of the red HPs have pretty narrow built-in optics, unfortunately.

 

[TheFishMan65]

I did a search on Mouser (or maybe Future), so I don't have link. If you can't find them let me know and I will try and track them down. They are older T1 3/4 gumdrop types. I thought maybe if the efficiency was close this would be cheaper and give better spread.

Apparently the Cree site is down so I am having trouble figuring efficiency but I found an Binning and labeling (Apr 08). The best Reds only produce about 40 Lumen at 350ma.

Ahha from led supply 3 up star 137.1 lumen at .35amps and 6.3 volts so 62 lumens per watt (must be a better grade then the old dinning and labeling). So not much more efficient than CFL, but all the spectrum is usable by the algae.

 

[TheFishMan65]

Ok so apparently Candella is light in a cone and Lumen is total light output. So there is not direct comparison, but I did find this:

You can't directly convert since they measure different things. The most useful explanation I've found is that lumens measure light output at the source, while candelas measure the light emitted per unit of solid angle, a quantity that conveniently does not vary with the distance from the source of the light. So, they measure different things, and there's no direct conversion. Update: I didn't find that answer very satisfying either, so I worked out the conversion details and made a conversion calculator for you to use.

Light bulbs and LEDs sold for illumination tend to carry ratings in lumens. Indicator LEDs tend to be rated in candelas.

You can also use this table to get an approximate conversion from candelas to lumens. Find your LED beam width in degrees, and divide the candelas number in your specs by the cd/lm factor listed for that beam angle to get lumens.

beam angle    cd/lm
5            167.22
10            41.82
15            18.60
20            10.48
25             6.71
30             4.67
35             3.44
40             2.64
45             2.09

 

[TheFishMan65]

Here is an interesting one (a link just for DWZM)
5200 lumen at 20ma and 1.85 volts and 30 degrees
so 5.200 / 4.67 (from table above) = 1.11 lumens
1.11 / (.02 * 1.85) = 30 lumen per watt
So half the efficiency of the XP-Es I found above. But it is only $0.20 as opposed to $12.60 for the one from LED Supply. Sounds great but you need 137.1 / 1.11 = 123 of these so $24.70. So the moral of the story is a good 3 watt LED is still better than lots (yes I mean) lots of little ones.

 

[Floyd R Turbo]

I'm not sure how this really applies. I know that the fixtures I had made contain 120 degree LEDs 3/4" OC and they're 1W each. They are blindingly bright and I have no doubt that they will grow algae very well. I understand the candela thing as this is a measure of light when you focus the beam into a specific angle, and if you allow the light to spread across a greater angle then you get a lower candela level spread across a greater angle. This is the point though of an LED fixture for a scrubber, you want the light spread out as much as possible so that you don't burn the algae.

For most people doing DIY, 3W LEDs will probably do just fine, but those are for the DIYers, and they are taking into consideration many other factors specific to their system. They can make modifications to allow for diffusion and distance specific to their setup/space limitations. A stock fixture with an array of 1W LEDs will be more robust for those not quite so handy.

Even coverage is the issue I am trying to achieve with the 1W array as I believe this is important for primary filtration and minimum screen size. the information you are posting is very interesting, I hadn't thought about any of that being a factor.

 

[TheFishMan65]

Actually the XP-E I mentioned above are only running at .74 watts for .35 amps so maybe 1.5 amps at 700. So in that sense they are 1 watt LED. Ah the fun of varying the current. Did you find a link to the ones you had made?

I will be replacing bio-pellets and people complain about the cost of replacing those. I have not replaced many and would hate to see the cost of electricity for the scrubber be more that the pellet replacement cost. That is why I am looking at efficiency. And because efficiency can vary so much I was trying to figure out a better rule than .5 watts per gallon. In the above cases effiency doubled does that mean .25 watts per gallon of good LEDs or 1 watt for bad LEDs. Now I think you see where I am heading.

 

[TheFishMan65]

Actually the XP-E I mentioned above are only running at .74 watts for .35 amps so maybe 1.5 amps at 700. So in that sense they are 1 watt LED. Ah the fun of varying the current. Did you find a link to the ones you had made?

I will be replacing bio-pellets and people complain about the cost of replacing those. I have not replaced many and would hate to see the cost of electricity for the scrubber be more that the pellet replacement cost. That is why I am looking at efficiency. And because efficiency can vary so much I was trying to figure out a better rule than .5 watts per gallon. In the above cases efficiency doubled does that mean .25 watts per gallon of good LEDs or 1 watt for bad LEDs. Now I think you see where I am heading.

 

[Floyd R Turbo]

you have to remember that the new lighting guidelines and feeding guidelines have kind of changed the rules. Originally it was 1 sq in per gallon, and 1 watt per square inch. Now it's 12 square inches or screen per cube of food (or equivalent). Also you can double the lighting to 2W/ sq in and halve the photoperiod to power through to the green algae.

From what I've seen for results from good DIY LED builds, it seems that LEDs were ahead of this game. The intensity of light in the spectrum that algae prefers without excess light in bandwidths that algae doesn't efficiently use seems to lead to green growth much more readily. So I still say that, as a rule of thumb, 1W LED per sq in of screen (dimensional, which means 0.5W /sq in on each side if you want to get picky) is what we should be shooting for. I can't recall what the wattage rating on the fixture I have it, but I believe it is in the range of 65W and I intended it to illuminate a screen that was about 8 x 15 but it may be slightly smaller, so I'm hitting this right at about 0.5 W/ sq in on each side with 2 fixtures.

If you go by the old lighting method, then yes you could go 0.25W/sq in on each side, or 0.5W/sq dimensionally. Just so I'm clear if you were trying to light up a 10x10 screen, 100 sq in, 50W LED total, 25W LED on each side, which 'translates' to 100W T5HO total, 50W T5HO on each side.

That is of course assuming that I am correct in being able to reduce wattage by half when going to LED vs T5HO/CFL. And this assumption mandates the use of 630/660 reds, maybe a blue or two, and NO whites, nothing else.

I like where you are going with this though. Really pinning down the exact efficiency of various types/brands/bins of LEDs could help you get the 'perfect' efficiency. Though I'm sure most people would just add a couple more LEDs and call it good, but you go man!

No word on the LEDs on my fixtures yet. Too busy...

 

[TheFishMan65]

If you go by the old lighting method, then yes you could go 0.25W/sq in on each side, or 0.5W/sq dimensionally. Just so I'm clear if you were trying to light up a 10x10 screen, 100 sq in, 50W LED total, 25W LED on each side, which 'translates' to 100W T5HO total, 50W T5HO on each side.

Not quite. What I am referring to is that the HP LEDs produce 60 lumens per watt. The gumdrops produce 30 lumens per watt. So if your fixture is 65 watts is it 3900 watts (60 * 65) or 1950 watts(30 * 65). Now say I want the same amount of light because I have the exact same fixture as you (you made it I just need to supply my own lights ). Without knowing which LEDs you are running I could get double the light (gum drops you HP me) or half the light (HP you gum drops me). I run the risk of poor growth from no light or burning the algae and my fixture is the exact same as your right down to the LED wattage. I post the problem :headwalls:

I know get dimmable drivers so the algae can be acclimated.:lolspin:

 

[Floyd R Turbo]

I see where you're coming from. It is very good that you brought this up. What is a gumdrop though?

 

[TheFishMan65]

Look up 5mm or T1 3/4 LEDs. They don't need MCPCB and are usually used as indicators.

This is close. Didn't look up the exact size of that one, but you will get the idea.

 

[Floyd R Turbo]

OK, that's what I thought they were. I would never recommend those anyways, only HP LEDs on stars or PCBs.

 

[TheFishMan65]

I thought they might be cheaper. I had just never done the math to figure out how many it would take. Many more than I thought (should have believed kcress). I still wonder how much variation there is in HP leds.

 

[Nathan.Titulaer]

I am restarting my scrubber project and was looking at Home Depot and they sell 2700 k Bulbs with LED's has anyone thought of using these? In my mind if the same kelvin works for CFL and T5 why not the LED bulbs? Mine won't be up and running until after new years but I have a 12x12 red and blue Ebay grow panel laying around I will use on one side and debating a LED bulb on the other.

 

[Floyd R Turbo]

$5 says that panel is the 'gumdrop' type LED that TFM and I just discussed. It has been tried, not intense enough. The home depot LED lamps are not grow lamps. CFL 2700k and LED 2700k are not the same. a CFL uses different combinations of phosphors on the inside of the lamp to achieve a certain color temp, so you can have 2 lamps with different spectral graphs and they will both be 2700K. LEDs are not that way, so they are not comparable. For scrubbers with LED you need something that is specifically a grow lamp. All red and maybe a few blues. It will not look like any lamp that you would put in your home. For instance, this is what the light I had made looks like when shining on my blinds in our house