Algae Scrubber Basics

[OllieNZ]

Originally Posted by jason2459

Wouldn't nitrate nitrogen be preferred over ammonia nitrogen until the nitrate nitrogen becomes depleted?

No plants and algae prefer nitrogen in ammonia form as they have to convert nitrate back to ammonia before they can use it
https://en.m.wikipedia.org/wiki/Nitrogen_assimilation

[jason2459]

Thanks for the link. According to that NHO3 Nitrate Nitrogen is the main form of N that they take in. Some C:N: P ratio.

"Plants absorb nitrogen from the soil in the form of nitrate (NO3−) and ammonia (NH3). In aerobic soils where*nitrification*can occur, nitrate is usually the predominant form of available nitrogen that is absorbed.[1][2]"

We're also trying to make this as aerobic as possible. We're also talking about a marine based algae and not a terrestrial plant.

http://www.ncbi.nlm.nih.gov/pubmed/17665646


Here's an interesting publication
https://www.google.com/url?sa=t&sour...Cc12F9O1ES3--A

Conclusion is ammonium doesn't inhibit nitrate uptake like thought especially in the right circumstances. In our application ammonium nitrate is already greatly depleted by bacteria. We're so providing the algae on the screen with lots of air and light for as perfect environment to grow. Nitrate will be the main form of nitrogen uptake. But more research can be done.

[OllieNZ]

A planted aquarium won't see a traditional cycle as the plants will uptake the ammonia for preference and plants will also respond much quicker to ammonia spikes than the bacteria can.
If you reread the article it just says nitrate is the most common form of nitrogen available not the preferred form.

[jason2459]

Originally Posted by OllieNZ

A planted aquarium won't see a traditional cycle as the plants will uptake the ammonia for preference and plants will also respond much quicker to ammonia spikes than the bacteria can.
If you reread the article it just says nitrate is the most common form of nitrogen available not the preferred form.

I'm not arguing preference as I have no idea and haven't seen the research on it and the one I did says more research is needed as it's not as preferred as expected. I'm questioning the amount of ammonia vs. nitrate taken up by the algae in our systems. Our systems not being freshwater or saltwater planted tanks. We should have extremely low amounts of ammonia in our system and should be undetectable because we have a large amount of nitrifying bacteria. We should have some detectable amounts of nitrate and phosphates. Even those people striving for ULNS will eventually dose nitrate and phosphate as they become limited.

In implementing Algae scrubbers of some type or a refugium for macro algae of some type we also try and provide enough light and water flow to allow for a very aerobic environment.

Both those scenarios to me would mean a lot more nitrate uptake and we really don't care about the ammonia uptake of the algae as it would be very minimal. If we did care then we haven't properly established our tanks. I wouldn't suggest someone dose ammonia or ammonium nitrate to their tank to promote algae growth but maybe someone has.

[fishbox]

What are pros and cons of waterfall vs upflow ATS?

[OllieNZ]

Originally Posted by jason2459

I'm not arguing preference as I have no idea and haven't seen the research on it and the one I did says more research is needed as it's not as preferred as expected. I'm questioning the amount of ammonia vs. nitrate taken up by the algae in our systems. Our systems not being freshwater or saltwater planted tanks. We should have extremely low amounts of ammonia in our system and should be undetectable because we have a large amount of nitrifying bacteria. We should have some detectable amounts of nitrate and phosphates. Even those people striving for ULNS will eventually dose nitrate and phosphate as they become limited.

In implementing Algae scrubbers of some type or a refugium for macro algae of some type we also try and provide enough light and water flow to allow for a very aerobic environment.

Both those scenarios to me would mean a lot more nitrate uptake and we really don't care about the ammonia uptake of the algae as it would be very minimal. If we did care then we haven't properly established our tanks. I wouldn't suggest someone dose ammonia or ammonium nitrate to their tank to promote algae growth but maybe someone has.

There are off the shelf aquarium ferts do use ammonia in some form or another as a source of N but even in the eyes of a planted tank hobbyist deliberately adding ammonia is not the done thing more due to the potential impact on live stock than anything else.
I'm not really sure what you're asking?

Will the algae uptake ammonia as a source of N? Yes
If there is insufficient ammonia to meet the N needs will the algae turn to nitrate as a source of N? Yes
Even though the algae is using nitrate it will still take up ammonia if it becomes available. Our well lit aerobic environment that we provide the algae with will have very little bearing whether there is ammonia available in the water we are supplying the scrubber with but if ammonia becomes present the algae will use it and will react to its presence much quicker than the bacteria can.

[jalisco]

Hello all,

I just wrapped up a consult that had me traveling for months which delayed the setup of my tank. I'm trying to plan my plumbing now.

I have a 45 gallon oceanic tech tank with center overflow. I've read that the 70g TT has a 650 gpm overflow but others said 800 gpm and I've found no info on the 45g. I bought an MP10wES to overcome the overflow's limitations as I plan on having some sweet sweet SPS.

Originally I was thinking the overflow would directly feed my Turbo L2 (with emergency bypass of course) so I could keep things simple and only have one pump in my sump.
Next I contemplated a dedicated return pump, sized ats pump and a third pump to run a skimmer when issues arise or when the ats lights are off. Looking at the 45g TT's stand I don't believe I can get a sump to accommodate three pumps.

Because I'm a sucker for shiny new objects I bought the Vectra M1 and planned on wying off the return to feed the ats and DT. If I install ball valves post wye fitting will that allow me to dial in the 35gph/linear inch of screen and still put the most gph my overflow will permit into the DT?

I plan on using my phone to put the tank in feed mode when I remove the ats screen for cleaning. This should allow me to close the ball valve pre ATS and not overwhelm my overflow.

What do you guys think? I am I on the right path or...? Always appreciate your input.

[Floyd R Turbo]

I have to read my Vectra instruction manual, does the "feed mode" shut the pump down completely, or does it just reduce the flow way down?

[jalisco]

I believe it either slows it way down or you can set how low it goes.

[fishbox]

Originally Posted by fishbox

What are pros and cons of waterfall vs upflow ATS?

No one? Just wondering what the preferred method is and why?

[jason2459]

Originally Posted by OllieNZ

There are off the shelf aquarium ferts do use ammonia in some form or another as a source of N but even in the eyes of a planted tank hobbyist deliberately adding ammonia is not the done thing more due to the potential impact on live stock than anything else.
I'm not really sure what you're asking?

Will the algae uptake ammonia as a source of N? Yes
If there is insufficient ammonia to meet the N needs will the algae turn to nitrate as a source of N? Yes
Even though the algae is using nitrate it will still take up ammonia if it becomes available. Our well lit aerobic environment that we provide the algae with will have very little bearing whether there is ammonia available in the water we are supplying the scrubber with but if ammonia becomes present the algae will use it and will react to its presence much quicker than the bacteria can.

I was/am doubting the statement that algae in our tank mainly uptakes ammonia. I also question the ability for algae to out compete bacteria in our tanks.

[Floyd R Turbo]

One could make the argument that algae actually can fuel bacteria. You could also argue that because of this, there is a possible symbiotic algae-bacteria relationship.

[jason2459]

I can see it working together in my tank where I dose a carbon source and harvest algae. I've been getting a good amount of bacteria growing in the inlet pipe feeding the ATS and the top of the screen that's in the pipe and is brushed off every time I pull it out.

[SantaMonica]

We should have extremely low amounts of ammonia in our system and should be undetectable because we have a large amount of nitrifying bacteria

When fish eat and pee, you get pure ammonia/urea that enters the water and travels to your glass before it hits any biofilms.

What are pros and cons of waterfall vs upflow ATS?

Waterfall: needs space above; can overflow; matts down after 14 days or so; can attach directly to overflow.

Upflow: needs no space above; can't overflow; does not matt down and can grow much longer; does not use overflow.

[Crusinjimbo]

Fishbox, I've tried both, upflow and waterfall, as well as a 30 degree slanted single sided. Space constraints in the sump drove these configuration attempts. All worked reasonably well but the upflow was the most difficult to service and requires an air supply to create the vertical bubble flow. Waterfall was most productive but takes valuable space above the sump. Evaluate your space available for your application and configure accordingly.

[fishbox]

Thank you

[jason2459]

Originally Posted by SantaMonica

When fish eat and pee, you get pure ammonia/urea that enters the water and travels to your glass before it hits any biofilms.
...

.

I believe it would travel in the water until it is consumed by something. Why would it necessarily travel straight to the glass? Why not my overflow, pumps, rock, sand, etc. whatever it hits first which is usually covered in bacteria. My glass will also have bacteria on it especially in my sump where I don't clean it.

[Floyd R Turbo]

Originally Posted by SantaMonica

Waterfall: needs space above; can overflow; matts down after 14 days or so; can attach directly to overflow.

Upflow: needs no space above; can't overflow; does not matt down and can grow much longer; does not use overflow.

This is the answer to "why is a UAS better than a waterfall" not his question which was

Originally Posted by fishbox

What are pros and cons of waterfall vs upflow ATS?

this is a better answer:

Originally Posted by Crusinjimbo

Fishbox, I've tried both, upflow and waterfall, as well as a 30 degree slanted single sided. Space constraints in the sump drove these configuration attempts. All worked reasonably well but the upflow was the most difficult to service and requires an air supply to create the vertical bubble flow. Waterfall was most productive but takes valuable space above the sump. Evaluate your space available for your application and configure accordingly.

Here is my pro and con list:


Waterfall (includes a slanted scrubber, and for the most part, a horizontal/raceway scrubber)

At minimum, you need a slot pipe or some other method to deliver water up so that if cascades down the screen, a roughed up piece of plastic canvas (Darice #7 mesh), a pump, and lights (usually on both sides) and a timer (for lights, water flow is 24/7)

Installation has to be above water or tank. Screen can be in sump below the "power off" water level, but lights cannot. So you need to support the slot pipe somehow, and it should be level. Difficult to incorporate into a non-sump system (but not totally impossible)

Since it can easily be 2 sided, you get double the growth area compared to a UAS of the same LxW screen (theoretically).

The water flow requirements usually dictate the use of a pump, because the flow rate is 35 GPH/in of screen width, so rates like 200, 300, 400 GPH actual flow across the screen (after head loss) are typical.

A waterfall scrubber creates a thin layer of high-speed laminar flow that allows nutrients to reach the algae. The laminar flow is what breaks the "boundary layer", which is the term used to describe the area that it microscopically close to the algal cells (flow goes to zero as you get closer to the algae)

A waterfall scrubber can form "streamer" if you don't protect the slot/screen junction. A 'streamer' is my term for when algae grows up toward the slot/screen junction and causes a pressurized point where water can spray sideways, literally horizontally, and get out of your sump. Adding Saran wrap over this area usually does a pretty good job of preventing the streamer, but not the growth. A blackout material does both.

Water can also "creep" along the pipe, adding a piece of airline tubing with a zip tie snaked through it and cinched around the pipe helps to prevent this, as does making sure the pipe is level (or placing it wholly within the footprint of the sump)

Water pressure prevents algae from actually clogging the slot/screen junction. Supplying the screen directly from the overflow will work fine because of this, but anything that goes down the overflow pipe (anemone, snail, etc) can block the flow, so you would need an open-end bypass unless you have a secondary overflow path that can handle the full return pump flow (so that you don't overflow your tank). Dedicated pump eliminates this, as does a return pump tap.

An open-screen scrubber cannot overflow. See above other issues

A closed-box scrubber can overflow, if not constructed correctly and (especially) if not maintained properly. Adding a secondary drain can help prevent an overflow (it will buy you time, essentially). Adding a removable/false bottom to prevent algae growth (and light) from having a direct path to the drain will help prevent the drain from clogging. But it basically comes down to making sure you maintain it or at least check it regularly, as it is not typical for a closed box scrubber to suddenly clog and overflow rapidly (not in my experience). This is because a closed-box scrubber tends to cause water to "build up" inside the box and suspend the algae so that it doesn't detached due to it's own weight, so the thing that would cause an overflow is too much algae growth - and since algae growth is gradual, not sudden, you get the point. As water rises, so does pressure, so a reduced drain flow will self-adjust when the water level above it increases. This of course will only work until the water level reaches the top of the box, but that comes down to monitoring the scrubber and knowing it's typical growth cycle so that you know when to clean it.

An open-screen scrubber can cause salt spray and salt creep on the lights, which may or may not cause issues with lighting, or generally annoying salt creep.

During a power outage, where the lights and pump shut off, an open-screen waterfall scrubber can dry out, but it takes several hours until damage starts taking place - but this depends on the point in the growth cycle, if you have a full screen, maybe 6 hours; a freshly cleaned screen might start to dry out in an hour. A closed-box scrubber will usually last a bit longer.

If a water pump goes out, and the lights stay on, the screen will dry out much faster

A waterfall scrubber can smell a bit during the first few weeks as the initial maturing happens, but this goes away as normal growth kicks in. After that, you would typically only smell the scrubber when you shut off the water flow prior to cleaning. And it doesn't gag you like skimmate smell does


UAS:

At minimum: need a substrate (can be canvas, but this is not ideal for a UAS - crushed quartz bonded to a solid panel has proven to be better), an air pump and air stone/bubbler, and lighting (usually only feasible to light one side)

Since it is usually only feasible to light one side, capacity is reduced when compared to a 2-sided waterfall (reverse of above)

When installed under water line, usually pretty easy to install by just dropping in the tank. This makes it adaptable to just about any tank, and makes it especially useful in biocubes or other sumpless systems.

Requires an air pump to operate, as the bubbles provide turbulence and water movement. The air bubbles are what provides the mechanism to break the boundary layer in a UAS.

Air pumps can be noisy by themselves and can vibrate up against something even if they are quiet, but there are ones that are pretty quiet and high-volume at the same time, so this is more about selection.

The water movement provided by air bubbles alone is much lower than that of a waterfall scrubber. So you get less turnover. If the UAS is a "closed" system (not just a screen strapped to an airstone, dropped in the sump) the constant motion provided by the air bubbles means that the water that is inside the box is recirculated and there is more contact time, so one could make the argument that the water is filtered to a higher level before it leaves the box. In contrast, an "open" UAS might have more inherent turnover by way of normal circulation, with the bubble providing randomness, but the flow might actually carry the bubbles away from the algal mat, defeating the purpose of the bubbles. So this comes down to construction.

Bubbles pop and this can cause salt creep. For an open scrubber, this can be an issue but it can also be remedied in various ways. For a closed scrubber, this can be remedied by placement of the unit such that the bubbles breach the surface within the unit.

On a power outage, the algae stays submerged so it can stay alive for days without too much die-off.

On an air pump failure in a closed UAS, with lights still running, the algae will eventually reach a point of photosaturation as there is no water movement and it will start to turn white and die.

A UAS will generally not smell at all until you take it out of the water to clean it


That's what I can think of at this point.

Generally, a waterfall scrubber has a lot more components and issues to account for related to construction and maintenance, but once you get that down, it's pretty much on autopilot.

The UAS is much simpler to build and more useful for smaller systems where you are not likely to feed a ton. But IMHO they don't scale up well to very large systems.

[fishbox]

Great info Floyd! Sounds like more of a personal preference to me. Tank is a 40B with 20L sump. I will have room to do either.

[mattberrytr]

Originally Posted by fishbox

What are pros and cons of waterfall vs upflow ATS?

IMO, choosing between an air bubble scrubber or a waterfall scrubber is pretty simple:

If you have the space for a waterfall scrubber, buy one or make one.
If not, buy or make an air bubble scrubber.

The potential downsides to a waterfall scrubber are completely outstripped by their much better ability to remove nutrients.

[salty joe]

What is the preferred material for ribbons or strings on a horizontal scrubber?

[fishbox]

Originally Posted by mattberrytr

IMO, choosing between an air bubble scrubber or a waterfall scrubber is pretty simple:

If you have the space for a waterfall scrubber, buy one or make one.
If not, buy or make an air bubble scrubber.

The potential downsides to a waterfall scrubber are completely outstripped by their much better ability to remove nutrients.

I've decided to do waterfall since I'll have the space.

[Spar]

My ATS is finally getting quick algae growth. Couple questions (see pics also).
(1) I do have some green algae, but it is otherwise quite brown, is this ok in early stages?
(2) I am getting a lot of algae buildup inside the pipe at the exit, is this normal, can it be fixed?

The algae was very easy to scrape off, if that helps with the assessment.

[karimwassef]

That looks line cyano, not hair?

[Spar]

Hmm possible. I do have a tiny bit in my sump. None in my DT though.

Thoughts on what i should/could do?