Algae Scrubber Advanced

[biglurr54]

I have very minimal rock. And it's been in the tank for over a year and the issue just started. I will increase the flow and add two more red leds. My growth is dark and slimy. Not emerald green and stringy.

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[Floyd R Turbo]

That first pic does not appear to be slimy - that's dense GHA, when you scrape it off, it might get gooey and such, but I wouldn't call the slime growth.

First, max the intensity

Second, max the photoperiod

Third, don't clean every 7 days necessarily. That's not a rule.

Fourth, when you do clean, don't do it aggressively. In fact, clean like this:





Tic-Tac-Toe on one side, cross-cross on the other. You can do this every 7 days if you like. It's more of thinning out than cleaning.

Growth sometimes comes in stages, you might be in one, The dense growth tends to shade the screen and lead to algae completely letting go, the above cleaning helps mitigate that

How old is the scrubber?

How close are the LEDs?

Pics?

[biglurr54]

When you say max the photo period, what is the max photo period. The leds are 2.5 inches from the screen.


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[karimwassef]

Max photo period = lights on all day and night

[biglurr54]

No breaks. I thought the algae needs a rest period to grow

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[karimwassef]

Corals do. Algae doesn't unless the food supply is exhausted.

[biglurr54]

OK will run 24 hours for a couple days and see how it goes.

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[Scrubber_steve]

Originally Posted by biglurr54

OK will run 24 hours for a couple days and see how it goes.

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Photosynthesis of Algae in Continuous Light vs. Light/Dark Cycles
http://reefkeeping.com/issues/2006-10/rhf/index.php

Interestingly, three marine microalgae, Skeletonema costatum, Phaeocystis globosa and Emiliania huxleyi, were studied for their rates of photosynthesis and carbon uptake mechanisms in continuous light vs. those same species in light/dark cycles (12 h on/12 h off and 16 h on/8 h off).

The rates of photosynthesis were nearly twice as high with light/dark cycles as with continuous lighting.

In two of the species (S. costatum and E. huxleyi), but not the third, the contribution of bicarbonate to the total carbon uptake increased dramatically in light/dark cycles compared to continuous light.

How this result might relate to growth and nutrient uptake in lit refugia where macroalgae are often grown to export nutrients is not known. However, it is a sign that perhaps continuous light is not optimal, in addition to being more expensive.

[Floyd R Turbo]

It is interesting but I would eventually like to see the data about macro vs micro. I'm not sure why the extended dark period really does anything special compared to a rapid on/off type of cycle, i.e. flashing.

Otto Warburg discovered long ago that flashing produces the same rate as constant light. In fact IIRC a high frequency flashing (like 1 kHz rate) of a light period followed by a dark period 10x as long produced the same rate of production. This was done by way of a wheel with slots cut in it, spinning inbetween the source and subject. (edit: this is old school, like 1930s stuff - around the same time he discovered the primary cause of cancer)

This has to do with the "dark cycle" of photosynthesis. Essentially, when there is light, a "bucket" fills up with "energy". During the dark period, this bucket is emptied, ready to be filled. When there is constant light, the bucket stays full and the process is less efficient.

The caveat is the waterfall action - this is akin to waves in a pool on a sunny day which produce contrast lines, we've all seen that, same thing happens in tidal ocean pools of corals (this effect was studied in Hawaii and published long ago). Same thing with a UAS and bubbles and the refraction of light as the bubble passes between the source and the algae. So in effect, this flashing action may already be occurring, which means lighting 24/7 might actually be the right thing to do (or at least, not the wrong thing)

So to me it would seem to be more logical to have a timer set to alternate on/off in minutes or even seconds rather than hours, or use PWM dimming to cause the flashing. Honestly I'm not sure if PWM dimming makes a difference or not due to the waterfall/bubble action but it certainly can't hurt.

Either way, any study that does not take into account some kind of flashing action is automatically biased against the real world use of algae scrubbers. i.e. if someone just studies algae growing in a vessel with the light shining unobstructed and unmodulated on to the subject algae. I would expect that type of study to show negative to no benefit to constant light, and thus a completely worthless study as applicable to what I care about

[Scrubber_steve]

Originally Posted by Floyd R Turbo

Either way, any study that does not take into account some kind of flashing action is automatically biased against the real world use of algae scrubbers. i.e. if someone just studies algae growing in a vessel with the light shining unobstructed and unmodulated on to the subject algae. I would expect that type of study to show negative to no benefit to constant light, and thus a completely worthless study as applicable to what I care about

You may have a point.

Some people have gone to 24/7 lighting & swear by it.

But I would ask why they needed to go 24/7 in the first place?

I mean, using a light-dark method my growth has been great, & the nutrients are scrubbed to a point where I look at lessening the duration of illumination.

[Scrubber_steve]

Originally Posted by Floyd R Turbo

It is interesting but I would eventually like to see the data about macro vs micro.

I've seen some disagreement in regards to wether the green hair algae that typically grows in an algae scrubber is macro or micro.

I haven't a microscope, but believe it is micro algae.

What do you believe it is Turbo?

[Floyd R Turbo]

Micro algae is more cellular, in suspension, like that they use for biofuel, etc. Macro algae attaches and grows in strands. I'm sure there is a more complicated explanation and I'm game for correction but I'm 99.2% sure that GHA is macro. 0.8% of me thinks I have no idea what I am talking about

[Zagzoo71]

My new 180g tank is up and finally running, I started it up with no skimmer. Idid a 10 x 12" algae scrubber, lights on both side, about 350gph pump. The lights are 2 LED 36w grow light bulbs. How's this look? Everything look right?



Thanks

[Floyd R Turbo]

Looks decent, except you can get rid of the dome reflectors. They pretty much do nothing for you unless you are using a Type A style lamp or a spiral CFL

[Zagzoo71]

Originally Posted by Floyd R Turbo

Looks decent, except you can get rid of the dome reflectors. They pretty much do nothing for you unless you are using a Type A style lamp or a spiral CFL

Well... had to use them to hang the light.. plus keeps some water from splattering on the lights

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[Devaji108]

Hey guys so I am at the point where I need to get my LEd lighting work out now I have my new waterfall scrubber. ( i took the UAS off line and my cyno came back oops )

so this is what I am thinking: for a 2 cube per day scrubber light on both sides
3 -660nm deep reds @ 700ma per side
1 420 nmhyper violet @ 350ma per side.

now the questions I have are should I go with 3 or 4 66o per side?
and I thought some where i read the 420nm should only be ran at 350ma is this correct?

[Floyd R Turbo]

I would use 4 660s, just because it's more even coverage, and the 660 is the primary driver for production.

I would run the violets at 50% of the reds, however you manage to do that.

[buddah001]

I built this ATS. Used a 20xh tank. Drilled the bottom to have it drain back in the sump. I taped off the area the light would be up against the glass and painted the tank silver first then black over that. Just trying to use as much light as possible. There are 2x 300w dimmable Mars Aqua grow lights. The screen fits into a slot in the pipe on top. Actually bought that portion on eBay. The screen or canvas is 12x18. What flow should this be seeing?

This is on a 135g display tank. Just set up 2weeks ago and going through its cycle right now.

I know this may be a little to big for this tank but I always go overboard on everything. I plan heavily stocking the tank and feeding real good. I also want to try and not worry about a skimmer too much on this tank

[buddah001]

[SantaMonica]

Nice build, but you'll need to keep the lights dimmed way down low.

[buddah001]

Originally Posted by SantaMonica

Nice build, but you'll need to keep the lights dimmed way down low.

Most of the systems I see on here the lights are fairly bright. I will keep an eye on it and see if it needs to be dimmed down. Luckily I have that option....

[Floyd R Turbo]

Dimming is almost a necessity for high-power LED arrays like that one. Initially, running at full power will almost certainly result in photoinhibition and the center of the screen will be bare, with growth filling in from the edges over time. The bare spot is because while there is not much algae growth, there is nothing else to adsorb the incident light energy, so it essentially overwhelms whatever algae is there and you get no growth. Literally, none.

However if you dim it way down (and I'm talking down to 50%, or depending on the density of your array in that fixture, you might turn it down to 10%-20%) then that will allow algae to grow much better initially.

Over time you can ramp up the intensity as you get growth kicking in, but even then you can reach a limit where more light intensity can cause growth reversal or even "whiting".

It's a balance between flow, nutrients, and light. You have to have it right for your tank/system, you can't always base your assumptions on what worked for someone else.

[wildman926]

Originally Posted by Floyd R Turbo

Dimming is almost a necessity for high-power LED arrays like that one. Initially, running at full power will almost certainly result in photoinhibition and the center of the screen will be bare, with growth filling in from the edges over time. The bare spot is because while there is not much algae growth, there is nothing else to adsorb the incident light energy, so it essentially overwhelms whatever algae is there and you get no growth. Literally, none.

However if you dim it way down (and I'm talking down to 50%, or depending on the density of your array in that fixture, you might turn it down to 10%-20%) then that will allow algae to grow much better initially.

Over time you can ramp up the intensity as you get growth kicking in, but even then you can reach a limit where more light intensity can cause growth reversal or even "whiting".

It's a balance between flow, nutrients, and light. You have to have it right for your tank/system, you can't always base your assumptions on what worked for someone else.

Great advice here!!

[buddah001]

Originally Posted by Floyd R Turbo

Dimming is almost a necessity for high-power LED arrays like that one. Initially, running at full power will almost certainly result in photoinhibition and the center of the screen will be bare, with growth filling in from the edges over time. The bare spot is because while there is not much algae growth, there is nothing else to adsorb the incident light energy, so it essentially overwhelms whatever algae is there and you get no growth. Literally, none.

However if you dim it way down (and I'm talking down to 50%, or depending on the density of your array in that fixture, you might turn it down to 10%-20%) then that will allow algae to grow much better initially.

Over time you can ramp up the intensity as you get growth kicking in, but even then you can reach a limit where more light intensity can cause growth reversal or even "whiting".

It's a balance between flow, nutrients, and light. You have to have it right for your tank/system, you can't always base your assumptions on what worked for someone else.

It is great advice and I will dim them down. I will do this until I start seeing growth then adjust as needed. Each fixture is 300w

[Floyd R Turbo]

Originally Posted by buddah001

It is great advice and I will dim them down. I will do this until I start seeing growth then adjust as needed. Each fixture is 300w

Oh yeah, most definitely dim those down, probably as low as you can go, or just a notch or two above it.