Algae Scrubber Basics

[Brummie]

Algae Scrubber Basics

Algae conform to the nutrients available. That's why different colors (species) of algae grow based on different nutrients and conditions. Even an individual species of alga can adjust its metabolism to conform to variations in nutrient availability.

If you google "algal luxury nutrient absorption" you can get a quick look at some studies on this.

If i try"algal luxury nutrient absorption", I get nothing useful at all. Perhaps my google machine is broken. I've tried variations such as "benthic marine algae luxury uptake" in the past and found no evidence of luxury uptake dependence on concentration, except in extremely high (15ppm) waste treatment ponds. Luxury uptake of P may be more important to marine algae as a short term storage of phosphate when the supply of P is intermittent, but this is used up quickly into biomass when conditions are favourable. From memory, different algae have different concentrations which may or may not be effected by temperature and irradiance.

 

[avandss]

Hey Guys! i would like to thank you all for all the help and info in this thread, it is quite the dedication!

here is my setup,

Tank
390 gallon system, 4-8 cubes a day (eventually)
system is 5 months old
currently has about 15 little guys in it!
current feeding 2 cubes a day

ats
i have it plumed to my return and i can get CRAZY flow from it
screen size is 8x10
running 60watt leds on both sides
http://www.ebay.ca/itm/60W-Quad-Ban...lue-Hydroponic-Floodlight-Lamp-/121210458918?
i took out all the white and replaced them with the reds (initially purchased 3 fixtures)

now i have growth just not in the middle, i am guessing the led's are too strong? i was thinking of covering it with some parchmen paper?
and i do not have any green growth
the ats is about 6 weeks old, i get lots of dark brown growth, this is after the third cleaning (10 days about)

 

[Floyd R Turbo]

I would say that you are correct, the LEDs are very strong. That's good, because once the screen is mature, it will grow well.

But initially, it's too strong. I don't know if I would use parchment paper, that might not handle the heat well. Get a 2'x4' sheet of diffuser from Lowe's (Plaskolite, with green sticker) for about $5 and cut pieces that you can tape on to the front of the fixture. You can cut the sheets with a box cutter, lay it on a work bench, put a straightedge or level on it, and make several light-pressure passes (cut on the smooth side) and you will eventually cut through it, or at least to the point where you can snap it. Wear safety glasses though if you score & snap, the stuff tend to shatter easily.

When you use the diffusers, you may be able to move the light closer. If you can't move the fixtures, don't cover all the LEDs with a diffuser, probably just the center 6.

 

[avandss]

thank you very much, everything else looks ok in your opinion?

 

[Floyd R Turbo]

Yeah, actually that's a pretty unique build. I like the emergency overflow on the inside. You might try to find a replacement for the rubber band, that will wear out eventually (and probably snap at the most inopportune time = Murphy)

 

[SantaMonica]

If you could back the lights away a bit, it will even out the coverage.

 

[DavidinGA]

I'm on day 20 of my new scrubber and now I'm getting a film on my glass that needs to be cleaned daily; what's the story?

I have zero nuisance algae issues and only setup the scrubber to help export NO3 primary (removing PO4 is just a bonus to me as I've never had PO4 issues).

My chaeto is still alive in the fuge, not running any gfo (stopped after adding the scrubber... That the problem?) and am still running everything else the same...

 

[Brummie]

I'm on day 20 of my new scrubber and now I'm getting a film on my glass that needs to be cleaned daily; what's the story?

I have zero nuisance algae issues and only setup the scrubber to help export NO3 primary (removing PO4 is just a bonus to me as I've never had PO4 issues).

My chaeto is still alive in the fuge, not running any gfo (stopped after adding the scrubber... That the problem?) and am still running everything else the same...

I assume your screen is growing a bit of unicellular algae growth, diatoms and green stuff (perhaps not filamentous). It is possible that exudates released from this algae actually favours unicellular growth elsewhere in the system. Once the growth on the screen is the filamentous type it is perfectly feasible that the exudates then released do not favour the growth of single cell growth elsewhere in the system, in fact inhibiting its growth.

A pic of your scrubber would be good

 

[DavidinGA]

Day 25 of scrubber

I have cleaned the screen once so far and am planning to clean it a 2nd time today or tomorrow.

 

[wildman926]

Day 25 of scrubber

I have cleaned the screen once so far and am planning to clean it a 2nd time today or tomorrow.

Keep up what you are doing. Have patience. Remember, you are trying to remove nutrients, not grow algae. If your algae is not growing so well, that may be a good sign.

 

[speedo2wet]

Well I created a new screen just longer than the first one I had. For some reason I thought the break in period would take a whole but seems that I started to grow HA rapidly. Also noting the growth in the tank mostly on the sand bed. The growth on the screen is not laminar but in patches which makes me think two things. 1-the flow has been dialed back to much. 2-the slot maybe to tight. Any opinions?

 

[flipstyle72]

ok, this is my weekend project!

 

[zabes]

floyd, what is your take on using an ATS on a predator heavy system? With the updated maths, I'm coming up with needing around 6-700 square inches of screen for the current amount of food fed.

 

[Floyd R Turbo]

Are you really feeding 50-60 cubes/day?

600 / 12 = 50 cubes/day
700 / 12 = 58 cubes/day

That is on the order of a a half-cup of food per day. That's crazy.

For a predator system, meaning no corals, you have much less to worry about w/r to fine particle food being left in the system for corals. So while you may shut off the return pump during feeding to make sure no food is wasted/filtered out in the short term, there would be no harm and likely a benefit to running a skimmer and filter socks. As messy as larger predatory fish are, these would still make sense to run.

The scrubber would help to reduce dependency on water changes to keep N and P in check, but you would probably still want to make it pretty large to be able to handle the bioload.

 

[zabes]

Are you really feeding 50-60 cubes/day?

600 / 12 = 50 cubes/day
700 / 12 = 58 cubes/day

That is on the order of a a half-cup of food per day. That's crazy.

For a predator system, meaning no corals, you have much less to worry about w/r to fine particle food being left in the system for corals. So while you may shut off the return pump during feeding to make sure no food is wasted/filtered out in the short term, there would be no harm and likely a benefit to running a skimmer and filter socks. As messy as larger predatory fish are, these would still make sense to run.

The scrubber would help to reduce dependency on water changes to keep N and P in check, but you would probably still want to make it pretty large to be able to handle the bioload.

derp. misread 12sq in as 12" x 12". :headwally:

i run through 1/2 to 3/4 lb of food a month currently with feeding 3x a week. so, if my math is right , i need a screen roughly 90 - 100 inches in size lit from both sides. currently run filter socks, supersized skimmer, gfo + carbon.

 

[speedo2wet]

I have to add: I have a 220
Predictor tank consisting of a sand shark, grouper and foxface and must say I am unable to grow algae in there. I may only feed them every 3-4 days heavily(foxface about daily) with its I get from the bait store. I do even feed live bait shrimp. I've also been running old t12 builds until
They blew out. Only think I can contribute to is the sand bed has always been stirred by the shark. Berlin method of rock and skimmer.

 

[DavidinGA]

I think I've hit the "oh ****" stage of my scrubber where green algae is starting to grow on my rocks in the display. Prior to the scrubber I have never had any algae in the display.

How long do you think the dt algae growth will last?

Scrubber is 23 days old and getting a couple small spots of the green turf algae growing on it now. Still only have the brown junk algae to clean off for the most part though.


Dirty screen

Cleaned screen

 

[speedo2wet]

@DavidimGA. I'm in the same boat as you are at this minute with my reef tank.

 

[Floyd R Turbo]

Dirty screen

Cleaned screen

David, when you post anything via tapatalk, right after you post you have to go in and "edit" your post then save it (without changing anything) or else everyone who is viewing it on a PC sees only the IMG code and not the actual picture.

 

[Floyd R Turbo]

As for how long it will last, this depends. There are many factors, and there are theories as to what the cause of this type of outbreak is, but they are only guesses at best.

While it is true that there can be an accumulation of detritus and/or water-soluble nutrients on the rock/sand, what causes algae to all of the sudden start growing after the addition of a scrubber is really not well understood, but we do know that it happens. But why would it not happen before you add the scrubber?

Some will say that you are lowering the nutrients in the water column and thus you get an effect of the nutrients dissolving into the water column more readily rather than the reverse. This is the theory that the rocks are like a sponge, taking in and giving off nutrients in relation to the environment around them. If you want to believe that, fine. But like a sponge that theory has a lot of holes in it.

Whatever the case may be, it doesn't happen to everyone. So that tells me it is somewhat dependent on the conditions of your tank and the long-term history of maintenance.

Bottom line is the stronger the scrubber (meaning, well built, proper flow, light, cleaning schedule, etc) the faster the scrubber will outcompete anything in the tank.