Refugium vs Reactor vs Algae Scrubber

[kmdrysdale]

I have been learning more about how phosphates and nitrates are a main cause of algae growth in our display tanks and have come across these three ways to help keep these levels as undetectable as possible. Now...I am new to saltwater and probably have a very limited understanding of each of these options and the pros and cons of each, but this is where I am at:

Refugium:
- can add some water volume to your system
- good place for chaeto
- safe area to produce pods for fish
- low maintenance
- could have a DSB here as well
- no extra operating costs

Reactor (with bio pellets):
- more of a chemical based system to reduce phosphates and nitrates
- (bi)monthly media changes required (continued cost)

Algae Scrubber:
- grow algae on purpose to keep it out of your display tank
- (bi)weekly cleaning required
- no extra operating costs

I'm sure I've missed details/pros/cons in each area, but hoping to learn from the experts here and learn from your experience with each method of phosphate/nitrate removal. Why have you chosen what you did? If you were setting up a new tank, which would you choose now? Do you combine one of the other options with a refugium? Any other wisdom you would care to share on this topic?

 

[seuadr]

wow, this is timely. I am considering the same question. subscribed!

 

[Gary Majchrzak]

don't forget

don't forget

protein skimming (which is more important than those 3 things already mentioned combined)


bookmark for future use

 

[HumbleFish]

One of the mistakes I made was not incorporating a fuge into my sump. I have a Mandarin pair, and really wish I had a fuge to cultivate pods safely away from my fish population. A fuge is also a great place to throw rogue crabs. And it just looks cool to have this little aquarium under your main tank.

 

[kmdrysdale]

I definitely appreciate my skimmer. So much sludge comes out of the water that looks clean it isn't funny!!

So you would say the biggest benefit of a refugium is a "pod factory?"

 

[HumbleFish]

So you would say the biggest benefit of a refugium is a "pod factory?"

Yes, sooner or later most reefers want a Mandarin. It usually happens on a whim. Problem is unless you've already got a healthy pod population going, a Mandarin will most likely starve to death. And then you've got to keep the pods reproducing, as Mandarins have high metabolisms and insatiable appetites. That's where a fuge comes in handy.

 

[blur456]

Reactor (with bio pellets):
- more of a chemical based system to reduce phosphates and nitrates
- (bi)monthly media changes required (continued cost)

newbie as well but from my understanding a reactor with biopellets is for removing nitrates. A reactor with GFO/Phosban is for removing phosphates. Use one or the other depending on what you want to remove (?).

 

[Rognin]

They sell regenerable (is that even a word?) nitrate resins for reactors. They last for about a month, then you soak them in salt water (NaCl) for 24hours and they can be used upto 250 times.

I think Brightwell makes them.

 

[degibson84]

I plan on running all 4 on my current build.

Gravity feed scrubber
Skimmer
Refugium
Reactor if needed. Already have one on my 75

 

[kmdrysdale]

Would there be enough minerals in the water for a fuge and a algae scrubber?

 

[Floyd R Turbo]

Generally, no, but that's not always true. It depends on how big of a scrubber you have and how many hours/day you run it. Also depends on size of tank, quantity you feed, etc.

I feel that having many forms of filtration is best - scrubber, skimmer, socks, fuge, carbon, GFO, carbon dosing, etc. You can undersize everything and the sum is greater than the need. Some balancing will eventually take place.

On the pods, a scrubber is a huge generator of pods and mysids. These become food for filter feeders and polyps. On every tank I have put an algae scrubber on, I see a huge ramp-up of sponges, tube worms, etc, and when I clean the screen I have pods all over the sink. In fact that is one of the reasons you are supposed to clean the screen ever 7 days or so, the pods eat the algae and can cause detachment if there are enough of them.

At our fall frag fest, Mark Vera basically said if you had to choose between a fuge and an Algae Scrubber, choose the scrubber. For a fuge to have the uptake capacity, you have to have a large and dense one, and prune it almost daily, whereas an algae scrubber is much more efficient for the space.

At our recent spring frag fest, Murray Camp spoke on advanced filtration methods and he does all forms of filtration including an Algae Scrubber and carbon dosing on the same tank and his algae growth is huge, goes against the standard tagline that you can't do both. I think he is using a powder dosing method developed by Hans Werner Balling (I think I butchered that name, German guy, you know!) as well as other C forms.

 

[Fitz19d]

Scrubber runs water over the "thing" and grows algae, I'm suprised to hear pods grown on it and not constantly washed away?

One thing that has me always curious. Either with a scrubber or refugium. How do you export sizable amounts of amphipod/copepods to DT? Like mine the baffles with sponges/carbon seems like it stops most things. Then the return pump has a prefilter. I know some get through, I see them in the return section. But no idea if they survive the return pump in the DT.

Do I really need to remove all the sponges etc to allow them to migrate, or how do I ensure good transfer if I'm trying to keep the DT seeded for mandarin.

 

[Aquatron]

You can have a million pods and other marine life in your sump, scrubber, or what ever but if you don't see your fish darting around your DT outlets.........there not getting to your main tank.

 

[Gary Majchrzak]

Would there be enough minerals in the water for a fuge and a algae scrubber?

personally, I've never heard the term "minerals" used in 'fuge / scrubber conversations.
What do you mean by minerals? Are you referring to major/minor elements in seawater... or waste products (nitrates/phophates etc)

Scrubbers and refugiums are PRIMARILY designed to perform different functions although they can cross over.

Scrubbers are PRIMARILY designed to reduce nitrates and phosphates (yet usually end up providing a sort of refugia for pods) and refugia are designed to provide a safe area for microfauna to reproduce (yet invariably end up providing a place for algae to thrive utilizing the uptake of nitrates/phosphates etc.)

It's my experience that most pods and microfauna survive a trip through the main return pump. Never block the intake of a pump with a sponge.

As I stated earlier, it's my opinion and experience that protein skimming trumps everything being discussed here.

 

[Floyd R Turbo]

Scrubber runs water over the "thing" and grows algae, I'm suprised to hear pods grown on it and not constantly washed away?

One thing that has me always curious. Either with a scrubber or refugium. How do you export sizable amounts of amphipod/copepods to DT? Like mine the baffles with sponges/carbon seems like it stops most things. Then the return pump has a prefilter. I know some get through, I see them in the return section. But no idea if they survive the return pump in the DT.

Do I really need to remove all the sponges etc to allow them to migrate, or how do I ensure good transfer if I'm trying to keep the DT seeded for mandarin.

When you get thick growth on the scrubber screen, pods will not get washed away.

Here's one screen from the other day

That mat it thick enough to actually trap detritus to some extent. When I scrape off the algae, pods are literally jumping around. Baby copepods are microscopic though, so there are thousands of them populating the screen by the time you scrape, and those can generally make it though to the pump, whether or not they survive the trip through the pump is up to debate, but if they did not, I would not think I would have seen the increase in filter feeder growth or the increase in pod population of the display tank after installing it.

I agree with not putting a sponge on the intake of a pump - never restrict the inlet, maybe just a strainer.

As for skimmers, nutrient export and gas exchange are just a couple very important functions they perform, so I agree that you should include one (a good quality brand)

 

[kmdrysdale]

Yeah...minerals was a bad choice of word. I was being lazy and didn't want to type nitrates/phosphates.

I would like to thank everyone for the replies so far. With only having a HOB skimmer right now and no sump, it has really helped me get a good grasp on some more benefits of each without actually having any of these 3 options running in my system.

 

[Fitz19d]

I think it's just the strainer/prefilter. It's a fairly course tube that fits over the inlet stem that came with it. (So gotta be intended right)

 

[BigAl2007]

I've been running an Algae Scrubber on my work tank for months now. After using one I don't plan to run another tank long-term without one. I've reefed for several years and I admit I was more than just a little skeptical about this whole ATS thing. Well not any more. I installed the Santa Monica UAS (HOG.5) on my work tank and the tank has never looked better. I was close to giving up on this tank and tearing it down (It's been up and running here in my office 5+ years now) because I could not get the GHA under control. Because it's in my office it gets the least care/love of all my tanks I've ever owned. It's just a pain to come back to the office after hours to clean/maintain it.

I installed the UAS and honestly for the first month I thought "This isn't working at all... there's hardly any green on the screen material". Honestly I sort of forgot about the UAS and didn't check it for weeks. One morning when the lights came on I was thinking, "What the heck is that green stringy stuff hanging off the glass on that one side?"

It was where the UAS has grown so MUCH GHA that it was spilling out from under the unit due to lack of cleaning. I honestly don't know it it was 4 weeks or 8 weeks since I had even thought about it but it was working. I'm not sure if I got pictures of the first clean-out but here are some of the 2nd clean-out




I now have zero GHA in this tank and only a small patch of receding Bryopsis in this tank and it's crystal clear. This all came about with NO changes other than the UAS. I didn't treat the tank or increase my water change regimen or anything. By growing the algae in an optimal environment (UAS) and then harvesting the growth I'm removing whatever the algae is feeding on in the main tank and exporting the growth from the system. I've noticed a slow-down in the GHA inside the UAS and I can only assume it's because the tank is more stable now and found it's equilibrium with the UAS installed.

Keep in mind this is in a 12g NanoCube but the new version from Santa Monica HOG1 will grow even more GHA and is for tanks with thicker glass. I know they sell the HOG1 UAS on Flea-bay and are worth their wait in gold. It's the single best piece of equipment I've added to a tank in a LONG time. I have a HOG1 UAS sitting at my house right now waiting to go onto my RAM130D.


In regards to "Pods getting into the DT" they will if you have good flow from your fuge into the DT. I ran a stand alone fuge in my 90g system that gravity fed into my sumps return section (yes with the return pump MAG18 sitting right there churning away) and at night you could see all kinds of pods getting tossed into the DT alive and well. It happened randomly (I guess when they got too close to the bulkhead in the Fuge etc) but with lights off and using a flashlight you'd see them occasionally get tossed into the water column and start swimming like crazy. In a few seconds some of the time the movement would catch the eye of a fish and GULP but also some of the time they swam into the Live Rock or somewhere else and the cycle kept going. Also when I harvested my Cheato I would let it sit on some egg-crate over the DT for an hour or so and the pods would drop into the water column...it was like candy falling from Heaven for the tank. I'm just trying to say they pods will get to the DT when the population in the fuge/sump is great enough and they WILL survive the trip. I'm sure some may not but those were eaten readily as well.

 

[Gary Majchrzak]

Big Al can we please see a pic of your aquarium?

 

[Floyd R Turbo]

IME UASs grow algae great, but very slow. That pic I posted is typical of 10 days of growth. My UAS grows 1/2 that much in 14 days.

Also I would have to say that your growth and mine are very comparable in the way that it is that bright green algae, and in my years of scrubbing experience you only get this when your tank is in good shape - that tank has P-0.00 on hanna and N=0 on Salifert. My other "dirty" tanks that I'm "cleaning up" with scrubbers grow algae differently.

Most any scrubber will do on an already low nutrient tank, and then it will do a good job of out-competing algae that has taken hold in such an environment. But IME only the waterfall has enough turnover rate to drop nutrients in a dirty tank, and then if it's a real mess, you need a larger scrubber, again IME.

Basically if you start everything out right and it's not all hosed up by the time you put on the scrubber, you will be better off