Is my refugium not needed?

[Murica]

I have a very large refugium with red ogo growing (or at least trying to grow), however I’m not getting the growth that I thought Id get. It’s not like my tank is nutrient free either, so there should be plenty of food for the ogo to grow. The Refugium has sand and rock.

I have an ATS that performs very well which is rated 400-1000 gallons. My display is 450 (model size, really about 300-350 with rock and sand) and I have about 200 in the sump.

In people’s opinions, is running the underperforming refugium worth it or should I turn off all the lights and just have it be a benthic/cryptic zone (whichever one is without lights). Are benthic zones beneficial other than growing sponges and providing surface area for bacteria? Turning off the lights will save me electricity but if it’s worth keeping the Refugium alive, then I’ll keep them on.

Thanks all.

 

[cilyjr]

I've never felt people running a refugium have one large enough for any real nutrient export.

 

[Gregg @ ADP]

It can be tricky, because we try to limit CO2 in service of maintaining a higher pH. But photosynthesizers need CO2 to drive the reaction.

What’s your pH? CO2 and O2 levels? NO3 and PO4 levels?

 

[Gregg @ ADP]

I've never felt people running a refugium have one large enough for any real nutrient export.

That’s more because they typically don’t regularly harvest the algae out.

 

[Murica]

It can be tricky, because we try to limit CO2 in service of maintaining a higher pH. But photosynthesizers need CO2 to drive the reaction.

What’s your pH? CO2 and O2 levels? NO3 and PO4 levels?

pH is around 8.1, no idea what Co2 and O2 are, no3 is 25 (was 75 a few months ago but I changed my husbands habits, got the ATS, and added the sand/rock to my Refugium), and idk what my po4 is

 

[Murica]

That’s more because they typically don’t regularly harvest the algae out.

Mine is fairly large so if it were growing like crazy I personally feel it would make a significant difference.

 

[KrisReef]

I think I would measure N & P for a few weeks before I shut down the refuge and let it go dark and continue measuring the N&P levels to see if I could detect any differences in nutrient uptake. If the numbers remain stable I would look into dosing silica to promote sponges and see how that impacts your nutrient levels.

Otherwise, having 2 light zones does provide redundancy for remote algae activity but a dark and light zone provides diversity in habitat that may improve your system?

Measure and report your findings. Please and thank you.

 

[cilyjr]

That’s more because they typically don’t regularly harvest the algae out.

I believe it is a lot more complicated than that.

Nobody is going to get much nutrient export from a small chamber in the middle of the sump packed with rocks, 1 sad mangrove stalk and a fist sized ball of chaetomorpha no matter the number of times someone pulls a few threads off the ball.

 

[The_Paradox]

I believe it is a lot more complicated than that.

Nobody is going to get much nutrient export from a small chamber in the middle of the sump packed with rocks, 1 sad mangrove stalk and a fist sized ball of chaetomorpha no matter the number of times someone pulls a few threads off the ball.

Mangrove is aweful for nutrient export. Chaeto is better or anything that’s fast growing. Chaeto in my sump is about the size of a basketball and gets ripped in half once a week or so. I think the problem a lot of people have with refugiums is their systems do not have enough trace.

 

[Gregg @ ADP]

I believe it is a lot more complicated than that.

Nobody is going to get much nutrient export from a small chamber in the middle of the sump packed with rocks, 1 sad mangrove stalk and a fist sized ball of chaetomorpha no matter the number of times someone pulls a few threads off the ball.

As always, the math matters.

Algae is very efficient at sequestering N and P, and when in a growth phase, the net amount of NO3 and PO4 algae removes for growth is not insignificant. I think @Randy Holmes-Farley posted some research showing how much of each is removed to grow 1g of algae. I don’t remember the #s, and they varied by alga type.

Sure, if somebody has a small amount and barely takes any out, it’s not going to change much. If you grow a fair amount and remove the majority that you grow every 2 weeks, you’re going to remove good amounts…especially of N, which is harder for the hobbyist to manage than P.

 

[cilyjr]

Sure, if somebody has a small amount and barely takes any out, it’s not going to change much. If you grow a fair amount and remove the majority that you grow every 2 weeks, you’re going to remove good amounts…especially of N, which is harder for the hobbyist to manage than P.

Hence the ATS being much more efficient use of the space.
I grow my chaetomorpha in a 5 g bucket plumbed into I'm tank. Works great.

My argument is a refugium full of fancy macro algaes, eelgrass etc. Is going to need to be a pretty big tank maybe bigger than the display to have real benefit.

 

[Spare time]

I've never felt people running a refugium have one large enough for any real nutrient export.

I ran my 75 and now a 48 refugium+socks+carbon and never do water changes. You simply need a powerful light.

 

[cilyjr]

Algae is very efficient at sequestering N and P, and when in a growth phase, the net amount of NO3 and PO4 algae removes for growth is not insignificant. I think @Randy Holmes-Farley posted some research showing how much of each is removed to grow 1g of algae. I don’t remember the #s, and they varied by alga type.

And again, are we talking about what's theoretically possible or what people are actually doing?
My father always used to say the problem with the world is its designed by engineers and not mechanics.

 

[Murica]

There’s gotta be more opinions out there on the benefits of Refugiums vs benthic zones!

 

[Gregg @ ADP]

And again, are we talking about what's theoretically possible or what people are actually doing?
My father always used to say the problem with the world is its designed by engineers and not mechanics.

Well, if people want to try to run a refugium along side a skimmer, GFO, carbon dosing, etc, then yeah…they won’t do much.

But if designed properly and not just one of 10 other nutrient export components, a refugium is more than capable of managing the nutrient load of a tank. I’ve done it countless times.

The key is to have fast growing algae and to harvest at least 1/2 of it at a time on a regular basis.

 

[mfinn]

There’s gotta be more opinions out there on the benefits of Refugiums vs benthic zones!

Refugiums, skimmers, scrubbers, etc are all just tools we use to remove n and p.
Everybody's situation is different, so go ahead and give it a try( removing the refugium).
See how it works.

 

[exnisstech]

I run chaeto fuges in all of my tanks. For me they have been poor at nutrient reduction but great for small life forms to live and reproduce so I guess mine are really refugiums not nutrient reduction chambers. I also added a semi cryptic zone a couple of months ago to one tank and and am getting quite a few sponges growing but I didn't start it to help with nutrient reduction. I just like all the different life forms that can live in a sump without predation from fish.

 

[Murica]

I run chaeto fuges in all of my tanks. For me they have been poor at nutrient reduction but great for small life forms to live and reproduce so I guess mine are really refugiums not nutrient reduction chambers. I also added a semi cryptic zone a couple of months ago to one tank and and am getting quite a few sponges growing but I didn't start it to help with nutrient reduction. I just like all the different life forms that can live in a sump without predation from fish.

Thank you for sharing your experience

 

[JNalley]

I didn't read all of the posts, so if this has been answered/addressed, I apologize. You mentioned in your op that you're running both a refugium and an ATS, and that the ATS is performing well. Running both is kind of redundant as they're both trying to draw from the same nutrient source, so the one with the better lighting will typically win out in the nutrient export game. Ogo likes fairly strong lighting as it's found in shallower areas off the coast of Hawaii. It also needs a fair amount of trace elements similar to chaeto in order to help it grow, you can pick up some chaetogro from Brightwell and see how it goes for you. I would personally keep the fuge and ditch the ATS as the ATS is only really good at Nutrient export, while the Fuge is good at that AND growing pods and other benthic critters to maintain your overall Biome. That's just my 2 cents though.

 

[Murica]

I didn't read all of the posts, so if this has been answered/addressed, I apologize. You mentioned in your op that you're running both a refugium and an ATS, and that the ATS is performing well. Running both is kind of redundant as they're both trying to draw from the same nutrient source, so the one with the better lighting will typically win out in the nutrient export game. Ogo likes fairly strong lighting as it's found in shallower areas off the coast of Hawaii. It also needs a fair amount of trace elements similar to chaeto in order to help it grow, you can pick up some chaetogro from Brightwell and see how it goes for you. I would personally keep the fuge and ditch the ATS as the ATS is only really good at Nutrient export, while the Fuge is good at that AND growing pods and other benthic critters to maintain your overall Biome. That's just my 2 cents though.

Thank you for that. The biggest reason I had both was that my nutrients were consistent with a FOWLR system (astronomically high), so I’m in the process of reducing them as much as I can. Now that they’re starting to level out, I’ll have to reconsider using it.