Algae Scrubber Basics

[wertoiuy]

Alright, I really don't feel like reading 385 pages, even though this has probably been answered: I don't have a tank and will likely not get one in the near future. However, I like to dream. I work at a local fish store which runs skimmers in sumps, but no live rock in sump or refugium, so I have to deal with skimmers all the time. I really like the sound of an ATS compared to a skimmer: the natural aspect appeals to me, and especially the fact that it wouldn't take miniature food that corals and small fish rely on out of the system (unless I misunderstand them). I also really like the idea of having a sump above above the DT rather than underneath, and installing a bell siphon into an end compartment to make a surge tank. I know that the bell siphon is used in aquaponics in order to provide a slow raise in water level and then a fast drain, which fully waters and nutrifies plants, but still allows their roots to breath. Would an ATS work just as well or better inside of this surge portion of the sump, or is it necessary to be constantly underwater? The thing is, to install an ATS otherwise requires another pump running in the sump.

Additionally, from what I gather, you can take all of the algae you pull out and feed it straight back to your fish? Does this essentially give you a sealed system, sort of like an Ecosphere? You would still have to dose things such as calcium & magnesium to account for coral growth, correct?

Finally, a really stupid question - What causes the algae to grow in the ATS rather than just in the tank like normal? The really strong lights?

 

[Wally.B]

I would only take the skimmer offline if your scrubber is active and healthy. You can try turning it down to experiment.

Took me a while to tune skimmer to perfection, so rather than turn down efficiency I'll put in on Controller to turn it off for a few hours during night.
Also I'll increase feeding to see if I can wake up the skimmer more. Or at least enough that the Snails and Cowrie can't keep up with their Scrubber Scrubbing.

If you have mechanical filtration, you're actively turning good organics into wasteful inorganics.

This is my experience.

I do have a Sump Sock, but it's under the water level under Tank Return Flow to capture only large particulate.
Reason for submberged Sock is I want live copepods, etc to have chance to escape. I just recently removed the bit a Active Carbon I had to see if it also helps Scrubber kick in. Nothing else.

 

[karimwassef]

I have to emphasize that most people use scrubbers to export. I experimented and have been successful with sequestration and recycling, but it's not the common use. In any case, I think algae is the solution - whether you sequester, recycle or export.

Some people can't put a scrubber large enough. Some people don't like the sound. Some people don't like the smell... there are solutions to all these issues, but that's my take on why scrubbers are not yet as popular as skimmers.

Any mechanical filtration creates waste. That includes skimmers. Large particulates are just bigger food. Some people can't stand the look of particulates in their water - I think it's natural. If you must have mechanical filtration, you need to clean it constantly to avoid creating waste. Every time you do, you're removing food from the tank.

 

[karimwassef]

Alright, I really don't feel like reading 385 pages, even though this has probably been answered: I don't have a tank and will likely not get one in the near future. However, I like to dream. I work at a local fish store which runs skimmers in sumps, but no live rock in sump or refugium, so I have to deal with skimmers all the time. I really like the sound of an ATS compared to a skimmer: the natural aspect appeals to me, and especially the fact that it wouldn't take miniature food that corals and small fish rely on out of the system (unless I misunderstand them). I also really like the idea of having a sump above above the DT rather than underneath, and installing a bell siphon into an end compartment to make a surge tank. I know that the bell siphon is used in aquaponics in order to provide a slow raise in water level and then a fast drain, which fully waters and nutrifies plants, but still allows their roots to breath. Would an ATS work just as well or better inside of this surge portion of the sump, or is it necessary to be constantly underwater? The thing is, to install an ATS otherwise requires another pump running in the sump.

Additionally, from what I gather, you can take all of the algae you pull out and feed it straight back to your fish? Does this essentially give you a sealed system, sort of like an Ecosphere? You would still have to dose things such as calcium & magnesium to account for coral growth, correct?

Finally, a really stupid question - What causes the algae to grow in the ATS rather than just in the tank like normal? The really strong lights?

Good ideas and I've implemented many of them - but to be more accurate:

A sump is "by definition" the lowest container in a system. If you want a surge tank over your tank, that's ok. Your DT is then your "sump". That means that your tank's water level will be the one that changes as water evaporates - just be ready to address this. Also, how do you plan to pump water up into the surge from your DT? An overflow container? Keep in mind that a surge can significantly overwhelm pumps - causing a sump DT flood... design carefully.

Surges are great. Passive surges like you describe are simple and easy to implement, but be comfortable with bubbles in the tank. I opt for actuated surges since I also run a heavy food system with lots of particulates. If I had particulates and bubbles, I wouldn't see the corals.

I think a surge scrubber would work - I have a thread on it since I'm planning one for my next tank. But algae grows best when it has a rich air/water interface. Either with bubbles or waterfall. Being constantly submerged or exposed for an extended time - both can cause problems. The surge would have to be frequent to avoid extremes, or add bubbles to keep air agitating the scrubber media.

I recycle - but you need heavy algae eaters to keep this cycle going. I use tangs and a rabbitfish to eat the algae as fast as it grows... they're my "sheep"

My theory is that scrubbers grow algae better they're "tuned" to grow algae better. The environment in the scrubber is optimum with lots of air/water interface, fast flow, and strong continuous light. Once algae preferentially grows in a location, it will continue to grow there - basically, it strips out the inorganics faster than algae in the tank.

It's a competition - algae in the tank is fighting the algae in the scrubber and the scrubber team is always winning. Add to that predation from snails, crabs and fish in the DT and those guys are toast...

My 0.02

 

[Wally.B]

Any mechanical filtration creates waste. That includes skimmers. Large particulates are just bigger food. Some people can't stand the look of particulates in their water - I think it's natural. If you must have mechanical filtration, you need to clean it constantly to avoid creating waste. Every time you do, you're removing food from the tank.

ok. I removed the sock that is just before the scrubber chamber of sump.
It wasn't doing much except catching food anyway which might help the scrubber and as you say the corals.
I can live with particulates floating in DT currents if SPS corals do better.

 

[Wally.B]

What is best way to restart my scrubber that went idle?

-> Reduce Photo Period?
-> Reduced Intensity?
-> Combination of both?

As I posted above my very active Scrubber went idle.
Still scratching my head why since plenty of Nutrients, N & P up there.
Let's put that aside for now.

I haven't pulled out the screen for a couple many weeks since nothing was appearing. Today I decided to look at their condition.

I did shoot TimeLapse Video and observed two Astrea's and one Cowrie polishing the screens with the little algae on there.

Astrea's have been removed, to cut back on screen cleaning/sterilizaton.

I smeared what little Algae was left at the Top of each screen over the cleaned areas. The areas they didn't reach since they don't like to come out of water. (These screen are submerged).

I don't need to rough up anymore, since there is good rough coralline on the screens (now). And they are prickly rough anyway.

Now I want to get screen going again.

My LED panel is dimmable (But I never used that feature).

I used to run 18-20 hours when Scrubber was active.
Now It's set at 12 hours to trigger some recovery and limit burn off.

Should I dim LED's and run more hours? Or run at max with less hours?

 

[karimwassef]

Confused by the picture. Why cutouts? Why multiple screen sections?

 

[Wally.B]

Confused by the picture. Why cutouts? Why multiple screen sections?

I won't try to explain the screens here.
Scrubber is my DIY custom design. A waterfall screen, but works like Upflow since submerged (and built into Sump, DT return Flow).
Worked great till this recent stop.
One screen is a outer basket, the cut out one is in middle and allows light thru (Cut out, where LEDs are placed).
I had a mirror before, but that was a bad idea.
Hard to explain here.
This THREAD Scrubber Build/Sump will explain it all. Shows Design Sketch, Build, Test Videos, and Scrubber Harvest results when it was humming.
(Page two will explain the cut outs)
http://www.reefcentral.com/forums/showthread.php?t=2570553
Have a peek when you have a spare moment and let me know best method to restart. Time or Intensity. Or both. or something else to solve this mystery (why it slowed down and stopped. It can't just be the snails and cowrie cleaning screens).

 

[SantaMonica]

Well you don't want coralline on it. It fights off algae.

 

[Wally.B]

Well you don't want coralline on it. It fights off algae.

I agree. But there is enough no-coralline areas on screen to start up.
I'll replace/clean the one or more screens later, once I get scrubber going.

I think I figured things out.
I did a review of all my Logs.
Posted Tank Log Review details at the end of my Tank thread.
http://www.reefcentral.com/forums/showthread.php?t=2636608&page=14
Summary:
-> Various Improvements to Tank lowered my N&P to much lower levels (over time). P especially
-> Scrubber Slowed down significantly (as it should)
-> Corwie and Snails cleaned Screen to Like New.
-> Screen can't start up since they keep it too clean.
-> I removed Snails. Will remove Cowrie.
-> I have to restart the screen like I started in the beginning. (15 hours, Full Power)
-> I have small head start with some algae on there.

Does my theory make sense?

What is better for restart. (High Power, Less Time) (Lower Power, More time). (Doesn't matter?).

 

[karimwassef]

Unless you're over 2000 PAR, I think it's just PAR x photoperiod - as long as there's enough food, I don't think the algae cares. Lower intensity for longer time is probably safer.

Sunlight on the reef surface is 2000+ PAR and algae grows fine... because there's enough food.

 

[vikinglord13]

Is it possible to "farm" a scrubber by putting algae onto it? What I mean is, rather than hoping a good photoperiod strategy will initiate algae growth, is it possible to just put a few strands of algae on the screen and allow them to take off?

 

[Wally.B]

Is it possible to "farm" a scrubber by putting algae onto it? What I mean is, rather than hoping a good photoperiod strategy will initiate algae growth, is it possible to just put a few strands of algae on the screen and allow them to take off?

That is exactly what is recommended according to what I have read (Priming the screen). What I did to get my scrubber startred..
Otherwise you just have to wait longer for floating aglae to attach to rough screen. You can actually choose the type of Algae that will grow on your screen. Some are better than others. Hair Algae grows faster, but it's messier to clean. Success varies with the scrubber design. My algae eventually was Thicker Macro, and I loved how easy it was to peel off the screen. (Macro worked in my Upflow scrubber, not sure if it's as good in a suspended Water Fall screen)

As I mention above, my scrubber shut down not too long ago. I wish I kept some of the previous Algae harvests in the refuge or sump so I could use a bit to restart the screens, by making a paste and painting it on screen to prime it.

The photo period is still probably important, to get the primed screen going.

 

[bbgobie]

Hope this is the right topic to post to.

Why not use a Chaeto reactor but inject air at the same time and grow turf/hair algae in there?

Seems you would have most the benefits of an external ATS except maybe quieter, less worry about clogging. With the disadvantages of probably harder to scrape/clean and less surface area?

 

[Floyd R Turbo]

I've seen someone grow chaeto in a modified waterfall scrubber box with a spray bar, so why not do the reverse? It might work

 

[SantaMonica]

The hair algae will grow on, and out-compete, the chaeto. This kills it. Chaeto is a very weak competitor for nutrients.

 

[SantaMonica]

Weekend growth pics:

 

[Wally.B]

I agree. But there is enough no-coralline areas on screen to start up.
I'll replace/clean the one or more screens later, once I get scrubber going.

I think I figured things out.
I did a review of all my Logs.
Posted Tank Log Review details at the end of my Tank thread.
http://www.reefcentral.com/forums/showthread.php?t=2636608&page=14
Summary:
-> Various Improvements to Tank lowered my N&P to much lower levels (over time). P especially
-> Scrubber Slowed down significantly (as it should)
-> Corwie and Snails cleaned Screen to Like New.
-> Screen can't start up since they keep it too clean.
-> I removed Snails. Will remove Cowrie.
-> I have to restart the screen like I started in the beginning. (15 hours, Full Power)
-> I have small head start with some algae on there.

Does my theory make sense?

What is better for restart. (High Power, Less Time) (Lower Power, More time). (Doesn't matter?).

Quick Update: (Scrubber Started and Speeding up)

I set PhotoPeriod for 20 hours, Intensity 90%. Yesterday I noticed the screens were getting greener (Non Corraline Areas), and hints of thick Macro Type Algae nodes forming.
On the Coralline areas, there were nodes of brownish, slime type algae.
The virgin screen (Small piece I added) two days ago was pretty well white.

Today I see as below, a Hair Like Algae attaced to the Airline, and the two Screens are being linked by Macro Like Algae Strands.
And the virgin screen is showing brownish color change.

Can't say cause was 100%, but maybe the snail and Cowrie was too much screen grazing when ATS slowed down (due to significant P drop).

 

[wertoiuy]

Do you all have huge, heavily stocked tanks or something? I thought our tanks were fairly heavily stocked, but we only feed an equivalent of 1 cube a week, not one a day. That seems like a crazy amount of nutrient inflow, and that is the baseline for sizing a screen.

 

[karimwassef]

I do

I feed solid food too - bananas are nice, and cheaper than seaweed per ounce

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