Hugbert's UAS Test

[Hugbert]

After aborting my waterfall design due to inadequate skill and motivation it was great to read about the breakthrough UAS - awesome work guys! I couldn't find SM's HOG UAS for sale here in Britain (Big untapped market?) so I made my own for my Kent Bio Reef (River Reef) 96l based on feeding 1/2 a cube per day.

Used small supermarket oven meal tray (welsh beef chilli con carne in case anyone was wondering)
3 x 4.5 inch plastic canvass (cactus rough) screen (will cut down to 3x4 inch when new air stone arrives)
Using Eheim 3701 air pump on full power (100 litres per hour, 3.5w)
Cut n shut 6 inch air stone - didn't work - 3 inch replacement on order
6w (3x2w) 3000k 240v E27 spotlight in a desk lamp about 3 inches away through glass - started with 18w 3000k CFL but wasn't spotlight and heated up tank way too much (+1.5 degrees after 8 hours)

Started it Sunday 8th July:
Day 1: 9.5 hours
2: 14.5 hours - noticed green algae starting to grow - strands of GHA from display getting caught?
3: Changed to LED going to try 18 hours a day from now on

How far should the LED lens be away from the screen? So the 'spot' fills the screen to edges?
Can I double the LED wattage and half the time? 12w LED for 9 hours?
Heat doesn't seem to be a problem at all compared to CFL's...

Advice much appreciated - thanks in advance!

[Floyd R Turbo]

Well for a 1/2 cube/day single sided screen (3"x4") you would only need 12W of CFL if that helps. The LEDs might work, but are kind of the wrong spectrum. 2700K LED is a marketing measurement really, meant to mimic other types of lamps. The spectrum given off by CFLs at 2700-3000K has a lot of red in it, LEDs in that range are mostly white so you would want a grow lamp LED with 660nm red. But I guess we'll see what it does, might be fine, you never know.

LED lamps on a UAS can be as close as you want really. CFL too for that matter but like you said it heated up the tank, so might need a fan on it or something (makes it complicated)

If you match LED wattage to what you would use for CFL, you're going to be at the double-wattage level. So if you went to 12W yes 9 hours. But that's with the right spectrum, hard to say what will happen with the 2700K ones. But just let it run and find out I guess.

[Hugbert]

Thanks Floyd I always wondered why SM used red 660nm led's in his HOB uas - will give the current led a week and see what the growth is like before changing it - I'll have to use the 3000k for interrogations - 40,000 hours should be long enough... ;-) I've found a replacement (see pic) 12w (12x1w) grow light but its got blue, orange and violet as well as red leds - still much better than the one I've got though?

[SantaMonica]

Real grow lights sometimes have extra colors. Try it and see. You can run it until the algae burns.

You probably are trapping stuff in the box. I do, when the output is below the surface.

[Floyd R Turbo]

That's more like it. You should be able to get those in all red 660 or with a few 455 blues also.

[Hugbert]

Today I spoke to a guy from an online LED shop who talked about having an E27 LED spot light made to UAS specifications - apparently I wasn't the first person to call him about it. So what is the best specification for a UAS LED? Would it be all red 660nm? Or better to have blues/indigo/violet too?

So far I've asked for 6w or 12w (preferred) all red 660nm LED E27 (screwfit) with 25 degree lenses if possible, no larger than 3 inches in diameter - I only have a 3x4 inch screen to focus the spot light on, so 6x2w would be better than 12x1w - 4x3w with lenses would be perfect.

The bulb in the picture is a 12w 3000k with lenses, did see Chinese manufacturer advertising it with red leds but no uk distributor - looks to be about 4 or 5 inches in diameter which would be too big for my screen but good for larger screens?

[SantaMonica]

It's probably the same as for plant growth, but I have not tested it.

[Hugbert]

That makes sense - I'll try a mixed grow light and let you know how it goes - thanks for the help and good job on the HOG, its a great design.

[SantaMonica]

Thanks... maybe I'll add blues one day.

[kerry]

Go with all red or red with a couple blues in it. I dont think the other colors would do much for you. By looking at what light the algae uses the other colors dont make sense to use.

[Hugbert]

Day 11 and growth is very poor (see pic) the 6w 3000k LED seemed to kill off the first 2 days CFL growth and its only really getting going again after 6 days of 12-14 hr 18w CFL.

Just to complicate things further I'm getting a 12w (12 x 1w) screwfit LED grow light (see pic - slightly different to one shown) delivered tomorrow to replace the CFL. It's mostly reds 660nm (x6) with 2 each of orange (615nm), blue (455 nm), and warm white (3700k); the warm white will be useless but it was the best I could find available!

The guy from that online store hasn't got back to me about the 100% red bulb yet so I thought I'd see how the grow light works out. I reckon Kerry, SM et al are right that vast majority red is the way to go - at least we can rule out 2700k+ LEDs for sure...

Story so far (more an example of what not to do!);

Day
1 18w CFL lamp 9.5 hrs
2 18w CFL lamp 14.5 hrs Screen starting to brown up a little, some GHA sticking to it and growing
3 6w 3000k LED Spot 15hrs
4 6w 3000k LED Spot 21hrs Screen almost completely white again, only GHA remaining
5 18w CFL lamp 17hrs
6 18w CFL lamp 12hrs
7 18w CFL lamp 12hrs
8 18w CFL lamp 12hrs
9 18w CFL lamp 14hrs
10 18w CFL lamp 14hrs
11 18w CFL lamp 14hrs - nothing like the kind of growth I should have.

Problems:

Too much heat from CFL so can't leave on for long enough,

didn't have a timer until day 6 so light timing very erratic,

my 18w CFL's are not 'spot lights' so the light is very diffuse and lots missing the screen,

tank is in my bedroom so can't have light on 18hr cycle.

Hopefully the 12w LED Grow light on 9 hours a day will be the answer...