Algae Scrubber Basics

[SantaMonica]

reading about how no3 and po4 are used by algae in a certain ratio

Algae use N and P in relation to how much is available; the algae consume more of what is available more, and this is called luxury intake.

If a scrubber slows down and can't get N or P to "zero", it's because the photosynthesis is weak. Increasing the photosynthesis will pull the remaining N or P down (if that is what you want to do).

Scrubbers do not replace skimmers. Airplanes do not replace cars.

 

[IanWR]

Anyway, when I hooked it up, my ATS stopped growing algae almost right away. My NO4 was too close to absolute zero but my PO4 slowly went up. When I started putting poison (NO3 stump remover) in the tank, the ATS re-started and the PO4 started coming back down.

Algae use N and P in relation to how much is available; the algae consume more of what is available more, and this is called luxury intake.

If a scrubber slows down and can't get N or P to "zero", it's because the photosynthesis is weak. Increasing the photosynthesis will pull the remaining N or P down

Ok this is what I mean, herring fish is talking about a situation where no3 was too low and causing the ATS to stop working. But would you (SM) say it was actually due to a lack of light? I really want to "get it" before I would try to put an ATS on my tank.

Scrubbers do not replace skimmers. Airplanes do not replace cars.

I suppose that's true. Typically one uses a plane to go to a different city and then a car to get you around within that city. So people who fly use cars. But I (mistakenly?) thought that you just run an ATS, "flying" everywhere you go. Still trying to figure out if ATS can be the main "mode of transportation" or if they can best be used as one of many.

- Ian

 

[SantaMonica]

Photosynthesis is not just light. It's light+flow+attachment+nonshading. If light is low or uneven, or the flow is lacking in air/water interface velocity, or the attachment is letting go, or the lower layers are being shaded by the upper layers, or even if the overall size is too small, then there will not be enough photosynthesis to to pump the lower nutrient (N or P) out of the water.

Since the ocean uses only photosynthesis for filtering on a reef, I choose to do the same. Being basically maintenance-free is a plus too.

 

[herring_fish]

Yes Photosynthesis has many requirements, an adequate amount of good quality light is only one of them. Good water flow allows algae to make exchange with what is in it, good turbulence helps to keep it able to continue to get good water flow to the surface of individual strand walls where the cells are. In the water, there is CO2, NO3, PO4 iodine, iron and other things that algae likes.

That is why a good design is important. If you have a well-designed unit that is properly sized for your tank, an ATS can work quite well. I swear by them and have used them for 20 years but I can't convince you nor do I want to try. You will just have to keep doing your research.

Have fun and good luck.

 

[IanWR]

I have enjoyed the back and forth found in almost any ATS thread on any site. I really appreciate hearing the voice of experience. I am so new to the world of ATS it's all still a bit to take in. There are also those that seem virulently anti-scrubber, suggesting that they will create a buildup of toxins, or discolour your water, or crash your tank, or what have you. There are such diametrically opposing views on some points there seems no way to synthesize them. Someone must be just wrong!

If ATS are as effective as the strongest proponents suggest they will be the future of reefing. If they are as good as the middle ground they will be an increasingly popular addition to the palette of filtration options and will help contribute to more successful tanks. If the most severe of the detractors is right ATS will fade away and join bio balls and other out moded approaches. Time will certainly tell one way or another. I just would like to be on the right side of history.

- Ian

 

[herring_fish]

LOL

There is normally a difference between I did and I think or I read.

 

[_shorty_]

From what I have read and experienced, bacteria is a big contributor to NO3 limitation and so I would think that a wet-dry could make things worse in that area. I see the carbon dosing people needing to use more and more GFO because bacteria loves NO3 but is not as good at eating up the PO4. Therefore, they are starting to dose NO4 so that the bacteria can get its fix and work on the PO4.

Interesting - I've read about the relationships of bacteria and consumption of NO3, PO4 and all that ... but have never made the connection that the bacteria developed when using a wet-dry would consume NO3. I think this is only because I have always read/heard that the negative affects of the wet/dry is described as a 'nitrate factory'.

Is it possible that we are talking about different types of bacteria when said growing surface is exposed to air, as in a true 'wet-dry' fashion? Or is that 'nitrate factory' term just way off? (I admit I haven't researched wet-dry much since 'back in the day' when setting up my first systems).

If it is the same bacteria - your statement makes complete sense, that carbon dosing is a similar tool 'on steroids'. However, if that's the case, I think that the wet-dry would still be a widely used tool.

Was your rock rubble totally submerged?

I think you'll find that systems are never limited by N or P. With the urine and respiration constantly going into the water, there is always a supply, and, the photosynthesis of a scrubber can make use of tiny amounts far below the test kit levels.

SM - I understand what you are saying.. but you don't think growth could be at least 'slowed' by lower nitrogen levels? That would in turn reduce the PO4 obsorption capacity. I guess that's what I mean by 'limited'... vs... I don't have any in my system.

 

[herring_fish]

Yes, in the old days, wet-dry filters grew different kinds of bacteria in the wet areas as opposed to the dry. That was part of the beauty of it. Also, back then keeping a very very lean tank was a primary goal of the strict interpretation of the Berlin method which was all the rage.

All of my rubble was submerged so there wasn’t much super aerobic bacteria growth. I also use vodka for a short time which promotes most bacteria in the tank as I understand it. Another thing about it is that a large percentage of the bacteria that is grown stays in the filter media, aside from what sloughs off and returns to the water column, unlike dosing carbon which promotes growth everywhere.

I really don’t remember the nitrate factory issue. I didn’t do any research on it. It just came with my first tank.

I am personally quite convinced that algae growth can be inhibited by an extreme lack of anything that it normally takes up. Now days, NPS coral growers feed tons of food and even SPS dominated tanks are being fed far more than they use to. This has to foster higher bacteria loads in the tank regardless of whether you dose carbon or not.

Bacteria can reduce nutrient loads lower than you might want. Most of the vodka guys normally use skimmers as opposed to algae scrubbers so they can’t speak to green algae growth suppression but they do sometimes report that there calcareous algae growth stops right away. I certainly oberved that in my tank.

I think that we are in an era that normally has higher bacteria loads in the water column than years ago so we might have to take that into our calculations from time to time. Unfortunately the side effects of these higher bacteria loads are just beginning to be understood. I sure don’t have a handle on it.

 

[salty joe]

I was thinking about a skimmer and an ATS and wondered about using a ReDox probe to turn the skimmer on when the ReDox potential drops to a certain point.
What do you guys think?

 

[Jerzey]

i'm on my 2 nd week of breaking in my ATS I'm not sure if this is common ...i've never had GHA problem in my DT only brown algae/diatoms but when it's bad they can over take my glass and LR....i know we're trying to get GHA to grow on the screen but how can it grow when little to none is present in my DT.... i did seed with as much GHA as i could find off my LR but at the moment i only have brown diatoms on my screen... how can GHA grow if little to none is present?... will it eventually take off once my screen is fully broken in in a few months ?

 

[SantaMonica]

growth could be at least 'slowed' by lower nitrogen levels?

I don't think so. In any nutrient absorption study (FW or SW), when one nutrient is available in excess, it is taken up in luxury intake so as to prepare for the future. Algae can store tremendous amounts of N and P like this. Googling "algal luxury phosphorus intake" will show some good results.

quite convinced that algae growth can be inhibited by an extreme lack of anything that it normally takes up.

Yes but there is no extreme lack in a tank. There is constant input with respiration, pee, detritus remineralization, etc. And this does not include feeding. You can have low measured P, but very high flux of P, too.

Kind of like taking a car battery at 12.00 volts, and touching it to another car battery of 12.05 volts. The voltage gauges in the cars would show "zero" difference between the two batteries, but once you touched them together, you would get a big surprise in amperage

 

[herring_fish]

Yes Algae can take up extra amounts of different thing much like we can store fat. When times are lean, algae can rely on that or just slow down metabolism or growth, much like we can. When levels get low, things get slow. That is one of the great points of Scrubbers.

There is a difference between zero on your test kit and absolute zero. The evidence shows that bacteria is far more powerful and far more dangerous to those that cause it to get out of control. It can lower N and P to levels that the aforementioned coralline algae, GHA, and lots of corals can suffer badly. If the situation is not remedied soon enough, stores will run out and bad things can happen. Bacteria can even strip out enough oxygen from the tank that it will crash. Both of these conditions can happen in hours not days.

Google shows that there are plenty of studies that back that up, in the lab, in algal farms, in treatment plants and in fish tanks. If we search this site, we can see that many people have issues with nutrient limitation. Nutrients can indeed be consumed far faster than any group of fish can replenish them.

 

[speedo2wet]

It always makes me ponder the question and I've said it once before. Even in the event that it becomes faded away just means that no large percentage of the reef keeping population attempted to try it out. Almost ever tank has experienced some algae bloom or ungodly looking tank, I say almost because I'm sure the majority of the population can in no way keep their tank free from excessive nutrients. Yet we spend vastly amounts of money in chemicals and other weird things to stop algae from growing (once it gets way beyond the clean up crew.) logically it seems right to promote algae in one area and utilize it's potential for the health of the system. I mean, isn't algae naturally all over a reef?

I'm hoping for a few things from my conquest into the ATS:
1) utilize the excessive CO2 in the tank and produce more oxygen, increasing and making the pH more stable.
2) creating a more healthier tank and visually stunning natural reef.
3) harvest algae to feed my other fish.

In the event this is successful, I will incorporate in my 220 gallon predator tank.

 

[IanWR]

Hi again,

I came across this article on another thread here http://www.advancedaquarist.com/2010/1/aafeature. Although it's 3 years old it had some interesting things to say about the limits of what skimmers can do, the lack of difference between skimmer designs, as well as the benefits of water changes.

My question is, is anyone aware of a similar experiment done with ATS?

- Ian

 

[inland]

Wet-Dry Tubes?

Wet-Dry Tubes?

We try to make it down to your shop as often as we can for as far away as we live. I used to live in TH and go to Rose... But wasn't in he hobby back them.

Anyway, I got in the hobby about 10-11 years ago and back then you ran those massive wet-dry tubes and recommended wet-dry along with most everyone else in the hobby. I guess that is not considering that 'export'? At what point did you decide to stop the wet dry? Because I've considered adding some on my (usually)NO3 limited system, and have often thought wet dry might bring a compliment to the balance (no3 vs po4) that an ATS provides.

We have always run ATScrubbers on everything. The only Wet-Dry that we have ever run here is on freshwater... currently on our Tilapia Grow-out system. I suspect that what you saw were our reverse Archimedes Screw pumps... large scale non-traumatic water pumps. We ran those on our Mini Display system, in front of the Observation Hallway, until about six years ago.

 

[inland]

Do you live there? I moved out of Phoenix in 1990. I started my first tank then and as soon at the book came out, I jumped on it. Sprung's tour must have been in 92 or 3.

No. I have been in Terre Haute, IN since '93. We did run an R&D facility in Phoenix around that time.

 

[_shorty_]

We have always run ATScrubbers on everything. The only Wet-Dry that we have ever run here is on freshwater... currently on our Tilapia Grow-out system. I suspect that what you saw were our reverse Archimedes Screw pumps... large scale non-traumatic water pumps. We ran those on our Mini Display system, in front of the Observation Hallway, until about six years ago.

oh! I was told early on by another hobbiest that those were a wet-dry system. lol.

 

[inland]

I was thinking about a skimmer and an ATS and wondered about using a ReDox probe to turn the skimmer on when the ReDox potential drops to a certain point.
What do you guys think?

Sounds good. It has been a decade since I monitored ReDox, but I suspect that, once the ATS is rocking, you will have to set the trigger point pretty high to see the skimmer kick on at all.

-MJL

 

[salty joe]

I don't want to control the ORP so much as use the skimmer for an emergency where I might not be around for a few days.

 

[SantaMonica]

What the skimmer do in an emergency?