Algae Scrubber Basics

[Lavoisier]

Interesting. Brummie, do you by chance know the effect of allelochemicals (I'm assuming from the hair algae in this case) in relation to distance?

[Brummie]

Originally Posted by Lavoisier

Interesting. Brummie, do you by chance know the effect of allelochemicals (I'm assuming from the hair algae in this case) in relation to distance?

No sorry. However, aquariums being a closed system would suggest that all tank inhabitants are right next door to each other. It is not ruled out that coral exudates do not effect algae growth also but I've not found much evidence yet. I've previously posted a link about giant nems directly inhibiting algal growth, so why not

[SantaMonica]

Friday night sizing guide posting:

What size scrubber do you need?
(edited July 2014)

The basic guidelines for algae scrubbers is based on how much you feed each day: 1 cube a day, 2 cubes a day, etc. However these are just starting points; a lot of your tank filtering is based on your rocks, so their condition plays a part too in what size scrubbers to get or make, as well as what type of feeding you are doing, and what other filters you will be using. This calculator is the starting point:

https://public.sheet.zoho.com/public...lculator-xls-1

...and here is a description:

Scrubbers are sized according to feeding. Nutrients "in" (feeding) must equal nutrients "out" (scrubber growth), no matter how many gallons or liters you have. So...

An example VERTICAL waterfall (such as the one I designed in 2008) or VERTICAL upflow (such as the one I designed in 2011) screen size is 3 X 4 inches = 12 square inches of screen (7.5 X 10 cm = 75 sq cm) with a total of 12 real watts (not equivalent) of fluorescent light for 18 hours a day. If all 12 watts are on one side, it is a 1-sided screen. If 6 watts are on each side, it is a 2-sided screen, but the total is still 12 watts for 18 hours a day. This screen size and wattage should be able to handle the following amounts of daily feeding:

1 frozen cube per day (2-sided screen), or
1/2 frozen cube per day (1-sided screen), or
10 pinches of flake food per day (2-sided screen), or
5 pinches of flake food per day (1-sided screen), or
10 square inches (60 sq cm) of nori per day (2-sided screen), or
5 square inches (30 sq cm) of nori per day (1-sided screen), or
0.1 dry ounce (2.8 grams) of pellet food per day (2-sided screen), or
0.05 dry ounce (1.4 grams) of pellet food per day (1-sided screen)

High-wattage technique: Double the wattage, and cut the hours in half (to 9 per day). This will get brown screens to grow green much faster. Thus the example above would be 12 watts on each side, for a total of 24 watts, but for only 9 hours per day. If growth starts to turn YELLOW, then increase the flow, or add iron, or reduce the number of hours. And since the bulbs are operating for 9 hours instead of 18, they will last 6 months instead of 3 months.

HORIZONTAL screens: Multiply the screen size by 4, and the wattage by 1 1/2. Flow is 24 hours, and is at least 35 gph per inch of width of screen [60 lph per cm], EVEN IF one sided or horizontal.

FLOATING SURFACE SCRUBBERS WITH RIBBONS: Screen size is the size of the box (Lenth X Width), and is 2-sided because the ribbons grow in 3D.

LEDs: Use half the wattage as above. 660nm (red) is best. You can mix in a little 450nm (blue) if you want.

Very rough screen made of roughed-up-like-a-cactus plastic canvas, unless floating surface, which would use gravel and strings instead.

Clean algae:

Every 7 to 21 days, or
When it's black, or
When it fills up, or
When algae lets go, or
When nutrients start to rise


HOWEVER, your rocks can supply much more "feeding" to your water that the actual food you put in, because rocks absorb phosphate, and once the rocks are "full" they will put this phosphate back into your water, adding to the phosphate that you are feeding. So the above sizing guidelines need to be modified in certain situations:

1) If you are building a reef tank which is new, meaning that the rocks are coming from the ocean or from a low-nutrient tank, and if you will just be feeding the fish sparingly, and if you DO want to have other filters and water changes, then you can just use the cube-feeding recommended sizes of the scrubbers.

2) If you are building a reef tank which is new as in #1 above, but you DON'T want any other filters or water changes, then double the recommended scrubbing amount in #1. This will supply the corals and small fish with the most amounts of food particles. You don't need to start the tank with all the scrubbers; one is fine for a few months. Add the others later.

3) If you are building a reef tank which is new as in #1 or #2 above, but the rocks are coming from a nutrient-problem tank which had measurable phosphate or hair algae problems, then the rocks will be soaked with phosphate and this will supply more phosphate to your new tank than the feeding will. So double the recommend scrubbing amount. And if it is a new reef tank with problem rocks AND you don't want other filters or water changes, you would need four times the scrubbing in order to handle the problem rocks and the other filters.

4) If you are adding a scrubber to an existing reef tank, and the tank has no measurable phosphate and no nuisance algae, and if you have other filters and water changes and you DO want to keep them, then you can just use the cube-feeding sizes of the scrubbers.

5) If you are adding a scrubber to an existing reef tank as in #4 above but you DON'T want to continue using the other filters or water changes, then double the scrubber amount recommend in #4, preferrably with an additional scrubber. This will keep filtering going in one when you clean the other.

6) If you are adding a scrubber to an existing reef tank that has measurable phosphate and green hair nuisance algae on the rocks, and you DO want to continue using other filters and water changes, then you can just use the recommended cube-feeding sizes of the scrubbers. Use stronger light if possible because the higher phosphate in the water needs brighter light to make the scrubber grow green. And if you double the amount of scrubbing (two scrubbers instead of one), the problems will clear up twice as fast because there will be twice the amount of algae absorbing the nutrients out of the water.

7) If you are adding a scrubber to an existing reef tank that has measurable phosphate and green hair nuisance algae on the rocks as in #6 above, and you DON'T want to continue using other filters and water changes, then double the amount of scrubbing recommended in #6.

8) If you are adding a scrubber to an existing reef tank that has NO measurable phosphate, but has LOTS of green hair nuisance algae on the rocks, then you need the strongest lights possible (for your scrubber size) because the rocks are already full of phosphate, and the algae on the rocks is absorbing this phosphate, meaning you need the strongest scrubbing possible in order to out-compete the algae on the rocks. This is the hardest situation to fix, so you should use as much scrubbing as possible with the strongest light available (for the scrubber size), and use as many other filters and water changes as possible too, until the algae on the rocks turns yellow and lets go. At this point coralline will start to cover the rocks, and you could consider selling some of the extra scrubbers, or removing the other filters or water changes.

[Floyd R Turbo]

Said it before, and I'll say it again. I don't think these "new guidelines" are proper, at all.

Also, since you can effectively increase the filtration power of a waterfall scrubber (to some extent) by increasing flow and light intensity/photoperiod after it is mature, it seems this guideline is more geared toward types of scrubbers which don't have this flexibility.

A 2 cube/day scrubber should be able to effectively filter 2 cubes/day as a stand alone filter. If it doesn't, then it's not a 2 cube/day scrubber. You shouldn't have to double filtration to 4 cube/day if you want it to be stand-alone. There's something fundamentally wrong with that whole line of logic.

[Brummie]

Smacks of a sales ploy to me, and an admission of failure. I hope he hasn't started to believe his own publicity as that's a cardinal sin in his line of business

[jimrawr]

How is the performance of the Surf2 -vs the HOG1? If they are able to filter the same amount, there is a large price difference between the two. Is there any reason other than ease of cleaning to pick the Surf2 over HOG1?

[boxfishpooalot]

Anyone have info about the importance of potassium to an ats? Also since istarted dosing iron to the tank the algae whent from brown to green!

[Floyd R Turbo]

Potassium is important. All fertilizer is NPK and algae is a plant. This is largely overlooked

[MorganAtlanta]

Just saw this on ebay. It's a pre-made hang-on-back led-lit algae scrubber with a roughly 5" square screen lit from one side. At around $100, it seems like a pretty good buy if you've got a small system.

http://www.ebay.com/itm/Algae-Scrubb...item3f3e5645a4

[Floyd R Turbo]

Well, it was only a matter of time before Hong Kong jumped on the bandwagon and figured out that your with LED, the algae could grow extra well, in your salty aquarium tank.

[jimrawr]

Originally Posted by MorganAtlanta

Just saw this on ebay. It's a pre-made hang-on-back led-lit algae scrubber with a roughly 5" square screen lit from one side. At around $100, it seems like a pretty good buy if you've got a small system.

http://www.ebay.com/itm/Algae-Scrubb...item3f3e5645a4

Not sure of the quality, but the idea of having a HOB Scrubber is great for those without a sump.

[DavidinGA]

Originally Posted by MorganAtlanta

Just saw this on ebay. It's a pre-made hang-on-back led-lit algae scrubber with a roughly 5" square screen lit from one side. At around $100, it seems like a pretty good buy if you've got a small system.

http://www.ebay.com/itm/Algae-Scrubb...item3f3e5645a4

That's pretty slick.

[wildman926]

I would be concerned about the strength of the build, and not break apart while in use on the back of the tank. Can you imagine the big mess it would be if it did? There is a reason why HOB filters are constructed in a one piece design.

[MorganAtlanta]

Originally Posted by DavidinGA

That's pretty slick.

A few users on the algaescrubber forum had done the same thing DIY with old Aquaclear HOB filters, so there's no great intellectual property here, but it is nice to see someone manufacturing that design.

[MorganAtlanta]

Originally Posted by wildman926

I would be concerned about the strength of the build, and not break apart while in use on the back of the tank. Can you imagine the big mess it would be if it did? There is a reason why HOB filters are constructed in a one piece design.

It looks like it is one piece, but with clear acrylic/plastic for the back window. The lights and screen just slide in, but aren't structural.

[wildman926]

Originally Posted by MorganAtlanta

It looks like it is one piece, but with clear acrylic/plastic for the back window. The lights and screen just slide in, but aren't structural.

You can't form acrylic with those hard edges. Look closer at the second pic that does not show the LED's on.

You can see the seams here between the main body and the lip overhang. Download the pic yourself and blow it up, and you will see it clearly -

[Floyd R Turbo]

Yes is it definitely hand-made, heat bent acrylic and solvent welded. Definitely not injection molded. Might be a stock HOB that was modified.

[Chris Abbott]

Can't speak to the quality of this unit, but if reputable vendor made it I would be all over it for a few smallers tanks.

[wildman926]

I have circled in red where the seams are visible....

[Floyd R Turbo]

Don't forget the far back corner. The vertical walls are made from one piece, bent with a line bender at 3 points, then solvent welded on the 4th corner.

The bottom edge would then be sanded flat, bottom bonded on, flush trim, add the rest to the front & back.

I'm guessing the lid is meant to also cover the LED chamber, which means condensation could find it's way back there. Bad design flaw.

You can see the rough-cut edges of acrylic on the lid and the top of the guide rails inside the box, which is fine, just indications that these are added not molded in place.

[Buzz1329]

Sorry, but I’m calling shenanigans on the alleged correlation between cubes of frozen food and size/design of an ATS. How in the name of Donn the Dark Lord of the Gaelic underworld can anyone determine what nutrients a cube of frozen food contains? There are dozens of brands and within the brands there are dozens of different formulas.

Even assuming that one could determine the contents of an average cube of frozen food, how the heck could anyone say that this ATS/filter/reactor/skimmer can capture the excess nutrients of a hypothetical cube of food within a 24 hour period? It’s preposterous. Res ipsa loquitur. The silliness of the thing speaks for itself.

[Floyd R Turbo]

You're correct. There really is no way to account for every scenario. I've made this point before elsewhere as well, maybe not the same way exactly.

For instance I feed a DIY food out club makes that is very "dense" and one commercial food maker told me he thought it would "overload your filtration".

The guideline is meant to get you in the general range of where you need to be. There are a few "guideline" factors that fall into this category.

Also, just to play devils advocate, if I feed 2 cubes/day on a consistent basis and I don't have any measurable N or P over a long term period (years) and the scrubber is my only filtration, literally the only filtration, and I harvest > 60g/wk of algae, and each feeding is about 6g (2 cubes or so)...pretty much exactly what you're saying is shenanigans is actually happening.

I have 2 tanks in this exact situation. I have another smaller tank like this also, which I feed proportionately the same.

[boxfishpooalot]

About that turf scrubber on eBay I had almost bought one but thought it's too small for 40 gallons total. It's probably like 4" long by 3" wide screen. That's pretty tiny, but would rock for a tank 20 gallons or less. If he makes them with a screen size 10" by 8" I'd buy one even at 150$-180. As far as the Santa Monica ats I personally think they are too much money and require stronger plastics. But I must congratulate Santa Monica for getting the enthusiasm up.

My question is how does an ats out compete algae in the tank? They don't? I assume snails gotta keep the tank clean.

[SantaMonica]

can anyone determine what nutrients a cube of frozen food contains?

Can anyone determine the nutrients in 100 gallons of tank volume?

[Floyd R Turbo]

Originally Posted by boxfishpooalot

My question is how does an ats out compete algae in the tank?

By providing a location where algae grows better, faster. That algae outcompetes the tank algae for it's source of growth.