What do you expect out of an algae scrubber and what difference has it made?

[RichReef]

We began renovating the room my original DT was in so I had to move the livestock to a 55 gallon I had set up in the basement. I used a 5 gallon bucket to put the macro algae in. It grew ok but couldn't keep up with the system.

I had a 20 tall tank just sitting there so I turned that into a waterfall scrubber just to give it a shot. I lit it with 2 LED grow lights from HD. I filled the bottom with rubble and the water level is about 3 inches deep.

After it had some algae growing on it the first thing I noticed was my PH got real stable and the macro in the bucket began to slowly fall apart. After about 3 weeks I pulled the bucket of macro and the scrubber took off. After about 6 weeks it was handling the tank with out a problem. I pulled the skimmer but soon after my PH dropped. So I put the skimmer back on with outside air and now my PH is a steady 8.2 ALL THE TIME.

After a few water changes I noticed the water had a yellow tint to it. I never really noticed this in the DT but it was very evident in the WC buckets. So I added a UV and that went away fast and my water clarity had improved drastically. Even better than before the scrubber.

So now it has never been easier for me to maintain my tank. The only thing that I have to keep an eye on is phosphate. About every 6 to 8 weeks it starts to creep up so I throw some Phosguard in the overflow for 4 days and it creeps back down and stays like that for another 6 to 8 weeks. I can always tell when the phos creeps up by watching my monti.

I an very happy with the ATS now and I'll be keeping it forever.

P.S. The room that's being renovated is very close to accepting a new build. This exact ATS will be in that build.

 

[Cory]

I made a diy waterfall version. It worked very well. No3 and po4 were always zero. I stopped for that because my coral paled from lack of nutrients. And i got tired of scraping it once a week. But i never adjusted the lighting to get my nutrients where i needed them. I could have ran the red leds for only 3 hours a day. This would have kept no3 and po4 enough for coral. That said they are good for po4 removal if you have nitrogen also.

 

[stacksoner]

-Expect it to not flood my apt when it gets clogged at the top of the screen and sprays water everywhere
-Expect for the lighting to not be unnecessarily heavy and obstructive unlike the outdoor wall-washing flood lamps they use
-Expect the design to be as compact as possible
- Expected that clear walls would allow me to view algae growth, but instead blocked by the huge lights.


This experience made me want to file a #metoo claim against Clearwater Scrubbers for charging $400+ for their garage-made product.

 

[Belgian Anthias]

The scrubber won't stop Cyano. Cyano is a bacteria. It usually thrives in clean water environments, as we have seen when customers are running a scrubber and it strips the water clean, they get an outbreak. It can be caused in dead zones, that's where the flow myth comes in, as food can mold in your tank and cause it. I would check to see if that is the case and make sure all food is eaten in the tank.

I have researched Algae scrubbers but have not decided to take the plunge since I am also considering dosing systems.. .that being said, I have a continual problem with cyanobacteria algae. I have had 3 'invasions' this year and am wondering if an algae scrubber would do the trick. I have been dosing with Dr. Tims, as per instructions, but it takes 3 weeks to get it to go away and some of my LPS are stressed when I am dosing.

Is this algae scrubber able to strip the water clean?
May high TOC ( molding food) availability cause cyano?

A good way to control cyano growth is competition. An algae filter is competition. Both algae and cyano are photo-autotrophs needing the same essential building materials. Cyano will win the battle from other photo-autotrophs only in nitrogen limited conditions. In a holobiont cyano will provide nitrogen by leaking it to sustain the holobiont in nitrogen limited conditions and are a key member of the community, in corals, in microbial mats.
In aquarium conditions, food not used should be remineralized as fast as possible and this is done mainly by heterotrophs. Food not used will increase DOC and TOC, a good reason for not overfeeding.
In high nutrient conditions cyano prefer to use ammonia-nitrogen to grow, just like most other micro-organisms.
Installing an algae filter may reduce or limit the growth of microbial mats but will not remove them as a microbial mat may be self-supporting, limited dependable of the environment. Once the microbial mats are removed (manualy) an algae filter may help in controlling regrowth.
Cyano ( microbial mats) can be removed by outcompeting them. This can be done by promoting fast heterotrophic growth by providing a high C:N ratio ( adding carbohydrates), taking up most nutrients fast. If cyano are outcompeted for nutrients all other autotrophs will also be outcompeted, including the coral holobiont and symbiodinium. As it may take weeks to starve microbial mats this can not be done without harming corals as the coral may not be able anymore to manage its holobiont and its food supply. In normal conditions, a coral is able to manage heterotrophic growth within its holobiont by excreting mucus (organic carbon and phosphorus source) this way stabilizing its nutrient supply. That is why it is advised to remove microbial mats manually.
An algae filter and or dosing carbon does not correct the nitrogen unbalance created.
A simple algae filter, grown in a refuge, is safe to use, easily manageable and is not sensitive to human error, which can not be said from the other commonly used on assimilation based method, dosing carbon.

 

[Rick Gaas]

I run an algae scrubber to control N03, P04. I adjust the scrubber time according to my tanks algae growth. I do daily AWC of 2 gallons on a 200 total volume system. No other water changes required, and SPS dominant tank. I will always run an ATS on any system I set up. Tanks will grow algae (FACT) so why not control where it grows from the start before it takes over rocks and coral?

What ATS do you run?

 

[JOKER]

I am running a clear water 100 I believe. I will have to check to be sure, but it works well for me.

 

[Jon Fishman]

My CW ATS

 

[Jon Fishman]

I have run a .5 drop Santa Monica scrubber in a 20gallon and a 75gallon. I have seen growth in both. 75 more so because I feed the tank more. I also run phosguard and carbon in the sump so I don’t know if that would affect performance. But to get them both started I had to put a piece of seaweed in there to get things growing. After that growth wasn’t perfect.

You talk a lot about growth, but my issue is...... I am growing sheets of crap to clean out, but do I need to be? Am I getting any benefit?

My EB8 is finally functional, so I guess I will put my scrubber on a day/night schedule

 

[PlasmaBoy]

i have noticed on the scrubbers I run that different light and different intensity grow different algae, low light you can grow cyano I'm actually using a huge Tupperware container of which I ruffed up the surface with sand paper to create a grip for algae to grow on. The surface is totally covered in a fast moving water with no air contact unlike a normal scrubber. I find I can grow dinoflagellates on these Out of the DIY world scrubbers represent the most cost savings of all. Mine was about $40 but DIY isn't for everyone, its not sexy to look at

 

[Sweetaz]

I cant grow chaeto so I dont think a scrubber would help

 

[Belgian Anthias]

Macro/turf algaes are much more reliant on NO3.

Most autotrophic organisms and heterotrophic micro-organisms prefer ammonia as a nitrogen source to grow. They will only use NO3 when ammonia is not available as in most organisms the enzyms (NR and NiR), needed to transform NO3 to usable NH3 within the cell, are repressed when ammonia is available.
As heterotrophic microorganisms grow a lot faster when using ammonia-nitrogen (+- x8) they will be able to use up most ammonia -nitrogen until there growth is limited by carbon availability.
That is why, in normal conditions, photo-autotrophs are more reliant on NO3, but they will grow at least 4x faster using NH4 as a nitrogen source. ( the nitrate level does not increase algae growth!!!!)
Some algae as Chlamydomonas are able to use positive and negative signals and are able to make a choice depending of the NH4:NO3 ratio. This makes them more competitive.

The best competitor for benthic cyano is another cyano, Synechococcus. It is a good food source for filter-feeders, grows very fast, can use NO3, NH4 and even urea. This cyano is not able to fix nitrogen.

An algae filter may be most effective when placed after a remineralization chamber, when the C:N ratio is very low. The filter may be able to use the produced inorganic nitrogen ( NH3) and phosphorus preventing these nutrients, products of remineralization, may enter the display. This also will reduce nitrate production. This can be done using a duo chamber refugium.

Dosing carbon ( high C:N ratio) in combination with an algae filter is not a good idea!! My opinion dosing carbon is never a good idea exempt to produce Bioflocs in a refuge.

 

[Josh@ClearWaterScrubbers]

I cant grow chaeto so I dont think a scrubber would help

The scrubber will grow a different type of algae. It’s more like a weed than chaeto and will usually grow in any system.

 

[Daniel@R2R]

Well after many years of seeing people use, make and talk about algae scrubbers I have decided to throw my hat into the scrubber ring and purchase one of my own! Lately I have seen an uptick in hair "like" algae in my frag tank and some short haired type algae in my main tank. They are both plumbed together. I want to be more careful with the steps I take to eliminate the algae due to the many acro frags I have in the tank now, so I decided on an algae scrubber and more of a natural approach. I needed a big one for my 450g or so system so I talked with Josh over at Clear Water Scrubbers and he suggested a CW-300. So I should have it this week.

So hopefully this will be a good discussion to learn about scrubbers and what to expect from them. I have questions for those who run scrubbers and those who do not run scrubbers.

1. For those of you who run algae scrubbers what difference has a scrubber made on your reef tank and does it meet expectations?

2. For those who have never ran a scrubber, that may be thinking about one, what do you expect to accomplish by running one.

3. What should we NOT expect to happen from running a scrubber?

Also found this video from @Afishionado where Josh talks about scrubbers and shares some great info.

Those clearwater scrubbers are dope! I'd run one if I had space for it.

 

[fredk]

Most autotrophic organisms and heterotrophic micro-organisms prefer ammonia as a nitrogen source to grow. They will only use NO3 when ammonia is not available as in most organisms the enzyms (NR and NiR), needed to transform NO3 to usable NH3 within the cell, are repressed when ammonia is available.
As heterotrophic microorganisms grow a lot faster when using ammonia-nitrogen (+- x8) they will be able to use up most ammonia -nitrogen until there growth is limited by carbon availability.
That is why, in normal conditions, photo-autotrophs are more reliant on NO3, but they will grow at least 4x faster using NH4 as a nitrogen source. ( the nitrate level does not increase algae growth!!!!)
Some algae as Chlamydomonas are able to use positive and negative signals and are able to make a choice depending of the NH4:NO3 ratio. This makes them more competitive.

The best competitor for benthic cyano is another cyano, Synechococcus. It is a good food source for filter-feeders, grows very fast, can use NO3, NH4 and even urea. This cyano is not able to fix nitrogen.

An algae filter may be most effective when placed after a remineralization chamber, when the C:N ratio is very low. The filter may be able to use the produced inorganic nitrogen ( NH3) and phosphorus preventing these nutrients, products of remineralization, may enter the display. This also will reduce nitrate production. This can be done using a duo chamber refugium.

Dosing carbon ( high C:N ratio) in combination with an algae filter is not a good idea!! My opinion dosing carbon is never a good idea exempt to produce Bioflocs in a refuge.

Thanks for the clarification. As I wrote, my memory is not so good these days.

I wish I had kept the text on plantbrain's explanation for why macro/turf algae out-compete cyanbacteria in higher NO3 conditions.

 

[krash7172]

I have a built-in eye level tank and not so much fun to enter since I need a ladder. I have a low maintenance mixed reef with mostly softies. Algae scrubber + modest cuc = clean tank for me. It's been at least 2 months since I put my hand in the tank other than to feed.

 

[nitrodude]

I tried one a while back. Santa Monica surf on my 400g. It was undersized for sure.
It did grow algae, but didnt notice mich of a decline in phosphate or nitrates. And the stupid airlines under it kept getting clogged with salt creep and were a pain to get cleared out. I got fed up with it and took it offline.
If the bigger waterfall scrubbers were cheaper I'd consider trying one again. They're just too expensive for me to justify trying again.

 

[Feet4Fish]

they aren’t too hard of a DIY project! Check out ATS build thread by @ca1ore

 

[SantaMonica]

Glad to see so many people using my waterfall vertical design from 2008. Yes it's easy to DIY.

continual problem with cyanobacteria algae. I have had 3 'invasions' this year

If you continue to export/remove nutrients with the scrubber, many times the cyano will go away too. Cyano need phosphorus and the scrubber will remove a lot of it. But just a simple CUC to consume food particles helps a lot too.

After a few water changes I noticed the water had a yellow tint to it.

On waterfalls, this is due to not cleaning the screen soon enough. The under-growth loses flow, dies, and turns into a yellowish hay material. Super strong lights in the middle of the screen, to create growth rings, will reduce this. And of course cleaning more often.

Bubble upflows don't have this problem because the growth is always underwater.

Expect it to not flood my apt when it gets clogged at the top of the screen and sprays water everywhere

Then install it down at the waterline.

Macro Reactor, I'm hoping it will help with the Cyano, red Slime

Macro/chaeto is usually coated with cyano. Chaeto is a weak photosynthetic filter, which is why you need such a large size.

I followed King of DIY instructions, cost around $35 for entire setup

That is my bubble upflow design; he did a great video back in 2013...

I went to a saltwater shop in Indiana that had been running for 8 or 9 yrs on a ATS and their tanks were crystal clear and thriving.

Inland Aquatics. Yes he had the first "licensed" scrubbers from Adey.

It grows not 1 type of algae which only uses a specific amount of something. It grows whatever to use up exactly the thing you have in your tank that needs to go out.

And not only that, but each algal species can alter it's chemistry to absorb more of what is available, when it's available.

It would also be possible that it grows algae which consumes ammonia which almost nothing else can consume till it turns into No3.

Yes all algae love to consume ammonia. A big fish feeding will put lots of ammonia/urea into the water quickly, and you will often see a doubling of scrubber growth the next day.

So if you compare any method that exists to pull out nutrients and try to prevent growing anything in your display, it’s an algae scrubber. I would even say it’s better than a skimmer.

And, a skimmer does not remove any nutrients at all. Only organic food particles. Of course you could feed less, but I like to feed more, and then watch the green grow more.

What is the heat affect of the scrubber?

None really of the LED itself. But if the 240/120 volt power supply is also attached like it is with the Chinese bolt-on lights, then you can get large heat output from that. Also there is a safety issue with the 240/120 volts near water.

I do wonder though, does algae scrubber has comparable affect on the tank's pH. My understanding is that it doesn't, because its theory is to give GHA the advantage of using CO2 from the air, so less are taken from tank water.

Yes it typically raises about 0.1 to 0.2 pH. Algae does not use CO2 from the air; it uses CO2 from the water.

much more biomass created per unit of time using chaeto or other macro algae than with my algae scrubber. So my thought process is more biomass = more nutrient removal. Any counter arguments?

Most of the biomass of chaeto is non-photosynthetic celluose, like a tree trunk with few leaves. So it just grows and nothing else, and, it blocks light. GHA however is all photosynthetic and blocks less light, like all-leaves. Here is more info:

"Production within dense mats of the filamentous macroalga Chaetomorpha linum in relation to light and nutrient availability"...

Wayback Machine

(also attached)

This is a good study, because chaeto is familiar, and because some people consider putting it in a refugium instead of using a scrubber. Fig 5B shows how, under bright light, chaeto productivity (filtering) drops 72 percent with just 2 cm of chaeto thickness.

 

[Turbo's Aquatics]

Super strong lights in the middle of the screen, to create growth rings, will reduce this.

I don’t know where you come up with stuff like this. Bare spots are caused by too much intensity. My original Rev 1 L2 had a single full-current Royal Blue LED right in the middle of the array on both sides, which caused a bare spot that was always the last spot where growth filled in on the screen (if it ever filled in there). It actually caused the screen to break down over time and become brittle, and in some instances it caused the acrylic in front of the LED to craze internally, all due to the intensity.

It’s not something you want or would ever intentionally design for in order to serve a purpose; there is no purpose for a “growth ring”. It’s a end-result of too much intensity in one location causing photosaturation. It’s a problem, not a feature.

I switched to 2 RBs in parallel (half-current) for Rev 2, which helped to reduce the persistence of bare spots but that didn’t completely solve the problem - the center of the screen would fill in with growth faster than before, but the edges always filled in first (basically, a slightly larger but less persistent bare area in the middle).

I changed the RBs to hyper-violets and added dimming for Rev 4 (also set to half of the current relative to the Deep Reds) and I haven’t had any reports of problems with the screen center filling in last. That essentially was how I solved that problem.

What is the heat affect of the scrubber?

None really of the LED itself. But if the 240/120 volt power supply is also attached like it is with the Chinese bolt-on lights, then you can get large heat output from that.

This is not true. LEDs produce heat, all of my versions have used 100% external power supplies (not mounted to the heat sink) but my heat sinks hit 100F at full intensity.

Also there is a safety issue with the 240/120 volts near water.

Maybe you should write some letters to the companies that sell products that use these fixtures in this manner, warning them of how dangerous this can be.

 

[nitrodude]

I don’t know where you come up with stuff like this. Bare spots are caused by too much intensity. My original Rev 1 L2 had a single full-current Royal Blue LED right in the middle of the array on both sides, which caused a bare spot that was always the last spot where growth filled in on the screen (if it ever filled in there). It actually caused the screen to break down over time and become brittle, and in some instances it caused the acrylic in front of the LED to craze internally, all due to the intensity.

It’s not something you want or would ever intentionally design for in order to serve a purpose; there is no purpose for a “growth ring”. It’s a end-result of too much intensity in one location causing photosaturation. It’s a problem, not a feature.

I switched to 2 RBs in parallel (half-current) for Rev 2, which helped to reduce the persistence of bare spots but that didn’t completely solve the problem - the center of the screen would fill in with growth faster than before, but the edges always filled in first (basically, a slightly larger but less persistent bare area in the middle).

I changed the RBs to hyper-violets and added dimming for Rev 4 (also set to half of the current relative to the Deep Reds) and I haven’t had any reports of problems with the screen center filling in last. That essentially was how I solved that problem.




This is not true. LEDs produce heat, all of my versions have used 100% external power supplies (not mounted to the heat sink) but my heat sinks hit 100F at full intensity.


Maybe you should write some letters to the companies that sell products that use these fixtures in this manner, warning them of how dangerous this can be.

Interesting read on the LED intensity.
When funding permits, I'd like to give one of your waterfall scrubbers a try on my 400g.
I actually had pulled my santa Monica surf out again to give it another try after first respond to this thread-we will see how long until the air lines clog again with salt creap.