The Super Guide to Algae Turf Scrubbers

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The Super Guide to Algae Turf Scrubbers

Part 1

Filtering your tank by using "algae to fight algae" has been gaining in popularity in the last few years. We are biased about this, because we invented the waterfall and upflow designs that everyone uses now, but nevertheless we wanted to make this in-depth series about everything, including:

· History of scrubbers
· DIY topics
· Commercial models
· Comparison to other filters
· Usage with other filters
· Sizing
· Lighting
· Water flow
· Operation
· Fresh vs. Saltwater
· Effects on animals
· Troubleshooting
· Dosing
· Types of algae
· Results in tank
· Uses of algae
· Safety

First, the origin of scrubbers should be mentioned. It was Dr. Walter Adey of the Smithsonian Institution in the USA who really got the scrubber concept going in the 1970's, when he was investigating nutrients and corallines on reefs:

Attachment 7736

His nutrient measurements confirmed what other researchers had found, which is that nutrients basically "stay on the reef" and do not flow out into the ocean, even though the water itself flows out into the ocean. It was already known back then that reefs are both generators and consumers of nutrients, consuming any nutrients as soon as they were available (thus making reef water "nutrient poor"), but he wanted to investigate further into who generated and consumed what, and by how much. He started publishing many reef nutrient studies, and came out with the first edition (now in third edition) of his Dynamic Aquaria book which describes in great detail about nutrient flow in reefs, corals, algae and animals:

Attachment 7737

Adey's big contribution to the aquarium community was in the separation of the nutrient generators from the nutrient consumers. The generators are the animals, micro creatures, and bacteria that all generate ammonia, whereas the consumers are the algae which consume this ammonia. On reefs this is all intermixed, and it keeps nutrients inside the reef, but he separated out the algae and created a device which mimics the environment where the most biomass of algae grew the fastest: where waves crash down on rocks. As soon as you scraped algae off of these rocks, it could be fully regrown in just 24 hours, and that's even while teams of herbivores were eating it. This could be a 100x increase in biomass in 24 hours, which absorbs a tremendous amount of nutrients from the water.

Attachment 7738

His device in 1980 used a dumping bucket to pour water onto a very shallow screen, and thus made a bubbling turbulent air/water interface that grew a lot of biomass of algae fast, and he called this device a "turf scrubber" because it grew a turf algae and it scrubbed (removed) nutrients from the water. By separating the nutrient producers from the nutrient consumers, the conditions for operation of the consumers can be controlled and optimized without changing the conditions for the rest of the reef (aquarium) itself.

Attachment 7739

Adey licensed the design to someone to have some small models made, but nobody ever really sold many of these dumping bucket designs because they were so big, complex, splashy and noisy, and also they were just 1-sided (top side) only which grows less. Also, Adey never had any interest in making or selling them himself, so they disappeared.

Later in the 1990's a few people made and sold the simple horizontal river design, like the Aquaricare scrubber which had little baffles to stir up the water and create a more turbulent air/water interface (the light on top is removed for the photo). But it too was large, splashy, hazardous (used high voltage T5 bulbs and wiring), and was also just 1-sided (top side) which meant it had to be larger to make up for less dense growth.

Attachment 7740

Then in the 2000's the last "different" version of an algae scrubber was introduced, the Eco-Wheel. This was a giant, expensive, complex rotating machine that did work, but no known installation pictures have been found; just this small photo from a sales ad:

Attachment 7741

And so, up until 2007 the basic algae scrubber designs were the dump bucket, horizontal river, and rotating wheel. And none were really being sold, so nobody knew about them. Then came "SantaMonica" (us!) on the forums in 2007, with the first waterfall style scrubber. The thinking was that there must be an easier way to get a turbulent air/water interface on a screen than using a bucket, a wheel, or a river. Let gravity do the work straight down! And a waterfall on a screen could have lights and growth on both sides, so it would grow more and could be half the size. This first waterfall was put into a bucket on a sink in the office, complete with dangerous CFL bulbs that got shorted by salt spray. This was all posted on various forums as "Waterfall Turf Algea Filter: CHEAP and EASY to build" if you want to read it.

Attachment 7742

It grew great, and brought nutrients down to zero with no water changes. But in order to get a waterfall in to our sump area it would have to be low-profile, so a custom acrylic box was made and the SantaMonica100 was born (100 was for 100 gallons)..

Attachment 8275

This was the first model to sell any real amounts. But it had flaws which caused it to be left behind in favor of our modern versions. First, it could not reliably be mounted anywhere but over a sump, because a clogged drain would cause an overflow onto the floor, or a clogged slot would cause water shooting out the top, even with a lid. Second, the cleaning/harvesting process was very involved, requiring water shutoff and disassembly of some plumbing or even taking the whole scrubber out. Third, the acrylic was fragile and easily cracked, especially after many heating/cooling cycles. And lastly, the high voltage 240/120 volt metal-case lights were dangerous for non-DIY users who just wanted a safe product. The lights would slowly corrode in the salty environment, and eventually short out.

And so there you have it; the evolution of the algae turf scrubber from the 1970's to today. We'll get into many other topics, but for now will just link to one of our smaller modern models, the HOG1, which is a great "starter" scrubber.

http://www.santa-monica.cc/product.asp?itemid=36

Attachment 7743

The Super Guide to Algae Turf Scrubbers: Part 2

By Santa Monica Filtration

http://algaescrubber.net/forums/atta...tid=7807&stc=1

Now let’s get into the first question that most aquarium folks have about scrubbers: Should you buy or build? Before the year 2010 there were not really any options to buy, but now you can buy tiny to medium size scrubbers in the upflow style, or medium to large sizes in the waterfall styles. And for building DIY, discussion forums now have examples of every attempted scrubber ever thought of, complete with growth examples and nutrient measurements over time. There are some really amazing builds that have been done. We won’t get into DIY plans here though because there are so many available elsewhere, such as our AlgaeScrubber.Net forum that goes back to the very first builds in the year 2008.

http://algaescrubber.net/forums/atta...tid=7808&stc=1

An algae scrubber can be made DIY fairly easily if you are good with building. The typical materials of pvc pipe, acrylic sheet, glue, airline, etc are needed, just as if you are building a DIY reactor, overflow, or sump. One difference with scrubbers however, which makes them a bit more difficult, is the lighting that’s needed for the growth. Not only are you now dealing with electricity, but unlike DIY display lights which are above the tank in a dry air environment that you rarely touch, the lighting for a scrubber is in a humid or wet environment (or even underwater) that you touch daily, with wet algae dropping on top of it, all while possibly standing on a wet floor (maybe even with bare feet). So don’t make a complex algae scrubber your first-ever DIY project.

Some advantages of buying a scrubber are that you obviously don’t need the time or space to build one. But other reasons are that it’s hard to DIY some types of scrubber designs, even if you are good with DIY. Things like underwater lights for upflow scrubbers, or gravel-epoxy surfaces for algal attachment, or the long slot in a waterfall pipe, takes a few tries to get it right (meaning your first try will probably not work).

http://algaescrubber.net/forums/atta...tid=7809&stc=1

Buying a pre-built unit, however, is limited to what is for sale. Currently the only models available are waterfalls (which we invented in 2008 and are now made by us and others) and upflows (only made by us), and these are in certain sizes only. There are a very few number of horizontal river models, but these are from China, are tiny, and are without any lights. And there are no dumping bucket designs available at all, probably because of their complexity.

The big advantage of DIY is of course money; most $300 USD commercial models can be DIY’d in a week for $60 in parts, and most of this is probably for the lights. But DIY also lets you choose the exact style, size, and layout you want to fit into your exact space. If you need a very large model, such as for small exhibits at public aquariums, you will have to DIY.

DIY waterfall styles are generally going to need some acrylic or plastic gluing, unless you can find the proper size plastic box to start with. Cutting the slot in the waterfall pipe is the hardest part, and although it can be done with a Dremel moto-tool cutoff wheel, most people end up doing it over again with a table saw, router, or other shop equipment. The lights are easy however; usually the low cost Chinese plant-grow lights can be used from Ebay, as long as you follow the safety steps such as shown in LEDsafety.org properly. Most DIY folks can do the pvc pipes, so that’s not a problem. Waterfalls are not really suitable for freshwater, however, because the growth gets long and clogs drains and pumps. Also, waterfalls work best when placed over a sump; not externally on their own, because they can overflow, leak, and also drip from the waterfall pipe.

http://algaescrubber.net/forums/atta...tid=7810&stc=1

DIY bubbling upflow styles can be the easiest, if they are similar to the Hang-On-Glass® styles that we make. These styles need no acrylic gluing or pvc pipe, and the LED lights just stick to a plastic cover on the outside of the sump or tank wall using magnets or suction cups. And the airline tubing for the bubbles is as easy as a goldfish tank. Cheap LED lights and a power supply from Ebay will do because they stay dry and are low voltage (no 240/120 volts at the light). These designs might be suitable for first DIY projects if you can get help with the lights, and are great for freshwater too because the long growth is kept mostly inside the growth compartment. Lastly, they can’t overflow, leak, or drip because they are already underwater.

DIY horizontal rivers are relatively easy to build; at least the river water part is. But again, the lighting can be a challenge over the long narrow pathway. One workaround for this is to put it under your display lights, but that’s just too cumbersome and unsightly for most people. And if put over a sump, these designs tend to cover the top of the sump like a lid, so you can’t get to anything.

http://algaescrubber.net/forums/atta...tid=7811&stc=1

If you have multiple tanks, a good bit of advice is to try a scrubber first on the smallest one, especially if it’s freshwater, because that way you can get a feel for placement, lighting, cleaning, sounds, etc. before working up to a bigger one. Meanwhile if you want to take a look at modern scrubbers, here is our SURF2 floating model, shown floating on a saltwater reef pond:

https://www.santa-monica.cc/product.asp?itemid=40

Happy Scrubbing!

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Attachment 7837

The Super Guide to Algae Turf Scrubbers: Part 3

By Santa Monica Filtration

Now let’s talk about the difference between fresh and saltwater algae scrubbers. They are different designs because the algal growth you get in each are different, and so the layout of the scrubbers needs to be able to handle this. Freshwater growth tends to be mostly Spirogyra or Cladophora species, which are very long (one meter) and very thin, like a string or thread:

Attachment 7838


This super long growth means two things: First, it’s going to try to flow with the water flow, which can be a very long pathway. And second, if the growth lets go, there is going to be long strings of growth finding their way through the aquarium pipes, pumps, etc. Since many freshwater people put the scrubber in their display (because they don’t have a sump) this long growth can get all over.

A plus for freshwater is that many of the fish that people keep (gupplies, goldfish, pleco’s, etc) love to eat this algae, so it can be an endless source of fresh free food. Matter of fact it’s relatively easy to have a freshwater tank that needs no outside food or waterchanges at all, and yet still has low nitrate. And the fish get to eat what they love the most.

Long freshwater growth is fine if your scrubber and installation are set up for it. Generally you don’t want a waterfall style for freshwater because the long growth flows right down the drain with the water flow, and can extend for a meter past that:

Attachment 7839


If it’s a waterfall in a sump, this growth will get caught up (or will clog) the return pump. And you can’t really put a waterfall over a display, so it must go in the sump. Thus waterfall designs are not recommended for freshwater. Upflow designs however are particularly suited to freshwater:

Attachment 7841


o Upflows are easy to DIY, by using a common air pump which many people already use for freshwater.
o Freshwater people usually want bubbles.
o Many freshwater tanks have no sumps, which is no problem for upflows because upflows can go into the display.
o Since filter units in freshwater usually go in the display, the fish can pull the algae out and eat it.
o The long growth is circulated around (and held) inside the upflow container, keeping most of the growth from clogging other filters or pumps.

Now let’s look at saltwater. The big difference with growth in saltwater is that it grows much coarser and thicker strands (Ulva species, etc) which tend to be curly but also much less long than freshwater. So you no longer have to deal with long growth that grows out of the filter, and this means that any version of a scrubber will work: upflow, waterfall, or horizontal river. But with saltwater you do have to deal with thick growth that blocks light.

The concept of blocked light is important because algae will die when light blockage occurs. And dead algae cannot hold on, so it washes away, and there goes your filter. It’s ironic: Thicker growth seems great, but it blocks light, which kills the growth. Dead growth is brown like hay, and can give water a yellowish look. So what to do?

Attachment 7840


Well fortunately the growth does not die right away; it takes a few days once the light has been blocked. So as long as you clean/harvest before the “roots” die and let go, you are good (algae do not really have roots but do have holdfasts which grab solid surfaces). A few tricks will let the growth go more days before die-off happens. You might think you could just reduce the hours of light so it does not grow thick so quickly, but this reduces filtering too and thus defeats the purpose of growing fast, not to mention it gives more hours of darkness which does not help the roots. So the trick is to grow fast but not shade the roots too soon. Here are some things to look for or try:

2-SIDED: A waterfall or upflow screen should be illuminated on both sides, so the roots that are grabbing the screen get light from both sides. This will let the growth go several more days before the roots get zero light.

STRINGS: Adding strings to a screen or a solid surface lets the growth grow away from the screen or surface, thus getting the roots out of the darkness. Strings by their nature are already 2-sided.

Attachment 7842


GROWTH RINGS: Usually the middle of a screen is where the growth is the thickest and the die-off occurs first. By using very strong light in the middle of the screen, this area can be kept un-grown until an outer ring grows first, thus keeping the middle alive longer. The term for this is “photoinhibition”.

Attachment 7843


EATING: By letting your animals eat some of the growth, the time for the growth to get too thick will be lengthened, or maybe, the growth will never get too thick.

Attachment 7844


ALTERNATE CLEANINGS: Instead of letting the growth go a full 7 to 14 days before cleaning, you can clean half of it every 3 to 7 days. Since you are cleaning / brushing / scraping right down the middle of the growth surface, this opens up the middle to more light.

SPLIT SCREENS: A more elegant way of doing alternate cleanings is to divide the growth surface in half, and clean each at alternate times. A waterfall screen is easily cut vertically for this.

MULTIPLE UNITS: The “most” elegant way of achieving alternate cleanings is to have multiple scrubber units. This achieves the same growth time for each growth area as above, but you do not have to deal with taking/leaving part of the growth behind, and you also do not tear growth in half which can put little bits of growth into the water. It also is the most expensive way.

Remember, the above information is for after a scrubber has been growing, or after you get through a slime stage. No scrubber will look or perform like this when brand new. For an example of a modern freshwater scrubber, here is a high power HOG2x with extra light for high nitrate water:

https://www.santa-monica.cc/product.asp?itemid=93

Happy Scrubbing!

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Attachment 8290


The Super Guide to Algae Turf Scrubbers: Part 4

(part 3 is here: http://algaescrubber.net/forums/show...ll=1#post41096)

By Santa Monica Filtration



Let's take a look at how scrubbers compare and work with other common filters:

WATERCHANGES: These can be done on any tank, at any time, and will not affect a scrubber at all. Waterchanges remove a portion of everything good and bad from the water, at that moment. Good things like visible food particles, invisible coral nutrition, copepods, microbes, and egg spawnings, along with bad things like ammonia, nitrite, nitrate, and phosphate. Medications are also removed, and this could be good or bad depending on what you are doing. But the important thing is that removal is only partial, and only at that moment; not before or after.

Scrubbers remove only bad things (ammonia, nitrite, nitrate, and phosphate) but leave all the good things (visible food particles, invisible coral nutrition, copepods, microbes, and egg spawnings) in the water. And scrubbers do this continuously (once growing), instead of only at one moment. Also, scrubbers actually add some more good things to the water, like copepods, amino acids, and oxygen.

For maintenance, the amount and type of work needed is quite different too. Most people will do waterchanges with tubing and a bucket, and if saltwater will also be buying and mixing a lot of salt. Scrubbers however in saltwater can be as simple as removing a handful of green hair algae, or a complicated as disconnecting pipes and tubes, and taking the whole scrubber to the sink for a brushing.

WATER CONDITIONERS (freshwater): Additives like Prime and Amequel are not known to directly affect scrubbers, however it's not very often that they have been used together. If you are using conditioners in an ongoing basis such as after every waterchange, then your tank is probably small enough that a scrubber would not be worth the effort. Generally, a 5 gallon (4 liter) tank is about as small as most people go with scrubbers.

CANISTERS (freshwater): Depends on what you put in them. Most canisters utilize some type of foam, which is detailed below. But sometimes they have other chemical pads; the only ones that would really harm a scrubber would be an algaecide or copper based treatment. If you only use foam and maybe carbon, then a canister and a scrubber will be fine together.

SKIMMERS (saltwater): Protein skimmers have no effect on scrubbers, and scrubbers have no effect on skimmers; thus they are often run together. Skimmers, like waterchanges, remove proteins such as visible food particles, invisible coral nutrition, copepods, microbes, and egg spawnings, but do it on a continuous basis. Fish waste, which is food for corals and inverts (especially sand-sifters), is also removed by skimmers. Scrubbers leave all this in the water, like a natural reef.

If you have corals and are looking to run your tank like a natural reef (which has tremendous amounts of particles in the water) then you will not want a skimmer. If however you are fish-only, and want water that is clear as a swimming pool, then you will want a skimmer. Skimmers however do not remove any nutrients.

Scrubbers do remove nutrients, such as ammonia, nitrite, nitrate, phosphate, CO2 and copper, which usually should be kept low or "zero" for corals. For fish-only, this is not really important; ammonia is the only one of interest but it can be handled by the bio coatings that accumulate on the rocks, substrate, and glass. If you have a large amount of fish requiring a large amount of feeding which generates a large amount of ammonia (such as a retail display), a scrubber would help greatly (once growing) with the ammonia removal, and you can feed a lot of the growth back to the fish, which reduces cost and food nutrient input too.

ROLL/FLEECE/FOAM/SOCK/SPONGES: These mechanical filters all do the same, and have no effect on scrubbers. They remove all particles above a certain size, but do not remove dissolved organics that are food for corals. When combined with scrubbers, the main benefit is to catch pieces of algae that let go; this happens most often on waterfall scrubbers. The drawback however is that herbivores don't get the fresh algae, and, planktivores like anthias don't get to chase food particles all day, including pods that grow in and fall out of the scrubber.

BIOPELLETS/CARBON DOSING: Carbon dosing, which started out as just vodka dosing, is now offered in many forms and brands, and does work to bring down nitrate and phosphate but can do so too much, which causes scrubbers to stop growing. Scrubbers will not affect the pellets/dosing, however. So generally when adding a scrubber to a pellet system, if nutrients and nuisance algae are bad, you can continue the pellets/dosing while the scrubber gets going, and then reduce the pellets/dosing when you are getting good scrubber harvests. If the scrubber is not growing at all after several weeks, and your nutrients are very low or "zero", then you will need to feed more (double, triple) or reduce the pellets/dosing so the scrubber can get growing.

If you already have a scrubber but want more nutrient reduction, and don't want a larger or second scrubber, then you can start pellets/dosing but do so very slowly. The growth cycles you were getting on the scrubber will probably change, and the growth will get lighter in color as the nutrient in the water get lower (dark growth mean lots of nutrients).

REFUGIUMS/CHAETO (saltwater): A refugium with chaeto and a grow light, or a dedicated chaeto reactor ("algae reactor", "light reactor"), operate the same as far as scrubbers are concerned. In general, you will not be able to run these together long term, although some people have done it.

A clump of chaeto generally needs to be about five times as large as the growth compartment of a scrubber, in order to get the same filtering capacity. This is because scrubbers pull nutrients out of the water much faster and stronger, per square inch, than chaeto does; so if you try to run them together, eventually the scrubber will out-compete the chaeto for nutrients and the chaeto will slowly die off. Meaning, the scrubber thinks the chaeto is just more nuisance algae to remove.

Some people start out with chaeto, and when they add a scrubber, both grow well. But if the chaeto continues to grow well after the scrubber has been harvested for many weeks, then the scrubber is not large enough for the job. So you probably should not count on having both operating long term, unless you want the scrubber to be lower-powered (smaller, less light, etc) so at to keep them both running together. This might be the case if you give chaeto to other people, but still want strong filtering; or if you like looking at chaeto but want green hair scrubber algae to feed to fish; or you just want backup, etc. Even if both start out growing well together, if you have old live rock with nuisance algae, the phosphate will start coming out of the rock and eventually your chaeto will start losing the battle. This could take a few weeks to a year.

GFO: Granular Ferric Oxide, or it's aluminum equivalent, can remove a lot of phosphate quickly but can really slow down or stop a scrubber from growing because the GFO is not biological; it's chemical instead. This means that it does not slow down removing phosphate just because the phosphate gets lower, the way algae does; algae will slow down growth when phosphate is low because the phosphate is the food for the algae, and with less food there is less growth. But GFO will continue pulling out phosphate way below the lower growth levels of algae, causing the algae to stop growing altogether, or to die off. So plan on not using GFO and scrubbers together, except for rare cases when nutrients shoot up and you need to get phosphate down quickly.

ACTIVATED CARBON: Granular Activated Carbon (GAC) does not remove any nutrients and therefore does not affect scrubbers at all. Some people want unnaturally clear water ("floating in air"), and for this you will usually need to run carbon with a scrubber. If however you are getting yellow water from a scrubber (usually a waterfall style), this is because the roots of the growth are dying and turning tan/yellow on the screen, because of weak light, weak flow, a dark or thick screen, or too long before cleaning; all of which starve the roots. Bubble upflow scrubbers do not have yellowing however, because they are always under water.

Interestingly, if a saltwater system is not mechanically filtered at all, then all the particles in the water will feed the periphyton on the rocks, and this thick periphyton will eventually consume almost all visible particles out of the water, and will even clear out most coloration that may have been visible before; all without any mechanical filtration or GAC at all.

UV: An ultraviolet sterilizer (UV) has no effect on a scrubber, and a scrubber has no effect on a UV. They can be run together no problem. If a tank has been running with only a scrubber for a while, and you add a UV later, you might get more scrubber growth for a bit because the UV is killing bacteria and microbes in the water and they are decomposing into nutrients that the scrubber takes up.

TRITON: The Triton method is an algal based method, so it has no problem operating with a scrubber. However, like a refugium, you will probably need to decide which direction to go: the algae in the refugium, or the algae in the scrubber. You could get lucky like some people and operate both for a while, but as nutrients come down, the algae in the scrubber will start out-competing the algae in the refugium.

ZEO: The different Zeovit systems can probably be best put into the carbon dosing (pellets) category, as far as scrubbers go. It depends on which Zeovit system/product you are using, of course, but in general, although some people can run them together for a short time, and a few lucky people can do it longer term, you should probably decide which direction you want to go: A zeovit filtered system, or an algal filtered system.

For an example of a small scrubber that can fit into the back of many nano compartments, here is a DROP1.2:

https://www.santa-monica.cc/product.asp?itemid=69



Happy Scrubbing!

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