Refugium or GFO?

[Daniel92481]

Refugium vs GFO?

I have an IM lagoon 25 and was wondering what would be the best option to remove phosphates from my tank. I perform regular water changes and my Nitrates are 5-10, while my Phosphates are 0.25 using the API kit which I will be upgrading to maybe a Hanna checker after I can get some advice here. I am looking for a nutrient removal/export system to help dial in my system. This is interesting to me that everyone has a different opinion on this. The refugium would be set up in the back baffle with a Chaetomaxx light from IM with an In tank marine fuge basket with some chaeto or caulerpa for the lagoon. As far as the GFO, I would use an IM desktop media reactor. What are the benefits of each? Disadvantages? For what it’s worth, I contacted Bulk Reef Supply and they advised refugium setup. To make things fair, I also called Marine Depot and felt they were leaning towards GFO.

What do the experts here on R2R think?

 

[chipmunkofdoom2]

Everyone has their own preferences and both will work. There are caveats to both though.

A refugium will remove nitrates and phosphates, and may have other benefits like reducing the diurnal pH swing observed in reef aquaria when the lights go out at night. A refugium is also self-limiting. If there are no nitrates or phosphates available, the algae will stop growing. It will start growing again once more nutrients are present. GFO will drive phosphates down to levels so low that they might be problematic. This is typically not the case with a refugium. A refugium, in my opinion, is easier to use than GFO. Simply trim some algae and throw it away every so often. With GFO, you have to stop the reactor, disassemble and clean the reactor, change the media, reassemble the reactor, and finally rinse the media.

GFO, on the other hand, is a bit simpler. You need to have a reactor and feed pump set up, but after that, just change out the GFO. You don't have to worry about getting the right lighting cycle for your macro algae, you don't have to order a light for the refugium, and you don't have to worry about having enough inputs to keep the algae growing (nitrates, phosphates, and iron). GFO is ruthlessly efficient at reducing phosphates. While this can be a con, if you use it carefully it's also a great benefit. GFO typically takes up less room as well. Instead of needing a large area where macro algae can absorb light and grow, all you need is a small cylinder a few inches in diameter. A big problem with refugia with macro algae (one I've experienced personally) is that some people just can't get the algae to grow. I don't think I've ever had a successful refugium that had growing and healthy macro algae. GFO works no matter what.

If I had to choose (and could actually grow macro algae), I would choose a refugium with macro algae over GFO. I like that the macro algae is self-limiting and usually does not drive the nutrient levels too low. I also like that there is no ongoing cost of media like there is with GFO. I also really dislike the changing of GFO media. Something about that chore always seemed far too labor-intensive.

 

[RobZilla04]

The Hanna ULR is great for testing phosphorus and converting to phosphates. Multiply the phosphorus ppb number by 3.06, then divide by 1000 to get phosphate in ppm. Only one powder reagent to worry about and testing takes less than 5 minutes.

Now for reduction. Based on your Nitrate and Phosphate numbers I would suggest getting confirmation on those numbers. Either a second Nitrate test kit or at a minimum waiting until you get the Hanna ULR to get a firm (and IMO more accurate) phosphate result. If confirmed .20-.30 I suggest using the refugium method. Couple of reason. Natural and will keep a more balanced reduction/consumption of Nitrates & Phosphates. Secondly GFO can be hard on existing corals acting as an irritant and/or it can strip the system of phosphates quickly causing stress to the coral.

Also consider a few large water changes. In a system as small as yours the most beneficial, simplest, least intrusive method to cut phosphates and nitrates in half is a 50% water change. You'll need to monitor feeding as a contributing factor to increased nitrates and phosphates. So long as your system is established and the rocks aren't leaching anything into the water, over feeding or poor filtration is the reason these levels would rise significantly after a 50% change.

Best of luck.

 

[Daniel92481]

Lots of good info here, just what I needed. With a refugium, and let’s say with a proper light setup, how long would it take the Chaeto to remove 5-10 nitrates? Should nitrates be higher to begin with before ever starting one? Should I continue to perform regular water changes or let the nitrates build up? I like the natural aspect of it, which is why it entices me, however the health of the corals is priority over my preference. With GFO, is this something to run continuously or titrate to effect? Would 0.25 Phosphates take 1-2 days to remove or closer to a week or two?

 

[Daniel92481]

Here is the email I just got this morning from Marinedepot...interesting.

 

[Fishyj]

I have a 20 gallon tall tank that my only filtration was my hob fuge. My chaeto will grow in a couple of weeks enough to fill my fuge. I have not measured phosphates, all I can tell you is I no longer have algae in my dt. I did also recently installed an ac70 to skim the film on the top of the water. I also do a 3 gallon water change weekly.

 

[LCC]

The gfo will lower your phosphates fairly fast. It can be run continuously or as needed. Keep in mind the discharge line needs to feed into your skimmer. If you can get a refugium to work for you go that route and do your water changes.

 

[Chris04]

I prefer GFO and all in one biopellets Keeps my phosphate down around .02 and if I get a spike will use phosphate RX to knock it back down

 

[mckinney0171]

I prefer GFO and all in one biopellets Keeps my phosphate down around .02 and if I get a spike will use phosphate RX to knock it back down

I ran GFO, biopellets, and a refugium at the same time. No issues with any of them.

 

[tastyfish]

I run a large refugium and GFO. The macro algae keeps nitrates very low and the GFO mops up excess phosphate. I find macro algae doesn't uptake as much phosphate as say, micro algae in an algae scrubber.

 

[Daniel92481]

I run a large refugium and GFO. The macro algae keeps nitrates very low and the GFO mops up excess phosphate. I find macro algae doesn't uptake as much phosphate as say, micro algae in an algae scrubber.

Oh I see. I’m new to all of this so just trying to see what will be the best method. Looks like I have some great options.

 

[tastyfish]

Oh I see. I’m new to all of this so just trying to see what will be the best method. Looks like I have some great options.

I can't recommend a refugium enough for various reasons, not just nutrient export. I think it's the best thing I did when I designed it into my system. I have never had an issue with nitrates, even with an overstocked tank.

 

[mckinney0171]

Oh I see. I’m new to all of this so just trying to see what will be the best method. Looks like I have some great options.

to me it is all about what you are trying to achieve. for me i wanted a refugium so that i could establish a good pod population. i also wanted to try carbon dosing and found biopellets to be a lot less work than vodka or nopox dosing daily. I also run GFO in all my systems but only change it out about once a month. I also feed like crazy (four times a day) and keep my tank stocked with lots of fish to keep my nitrates and phosphates detectable.

 

[Crabs McJones]

I prefer refugium, as it removes both phosphates and nitrates, and provides a good home for pods to populate

 

[Daniel92481]

That’s another really good reason to have a refugium, is to give pods a safe place to populate. Looks like I will be going with a refugium as my first option. I’m going to order the IM Chaetomaxx light, In tank fuge basket, and a ULR Hanna checker. Thanks peeps! I knew I could count on y’all.

 

[lion king]

Your nitrate to phosphate ratio is out of whack, my nitrates run between 10-15 and when I get phosphates above .08 with the hanna ulr I get cyano to let me know there is an issue. For me macros seem to run my tanks balanced with a proper nitrate and phosphate ratio. Since your nitrates are under control and your phosphates are out of whack, I'd run gfo.

 

[Daniel92481]

Well R2R, decision made. I just ordered the IM Chaetomax fuge light, In tank fuge basket, light timer, Hanna ULR kit, and a set of test reagents. I’m hoping this fuge set up, along with regular husbandry will reduce my current Nitrates(5-10ppm) and Phosphates(0.25), to a lower level without stripping them completely.

 

[Daniel92481]

Just set up the refugium in the lagoon with a tennis ball size of chaeto. I have it set on a reverse timer from my display to help with any PH swing at night, if any. I was also able to check my Phosphates with the Hanna checker. 12PPB phosphorus which equates to 0.037 Phosphates. My nitrates were at 5. I’m hoping to lower them both by a small margin, decrease small amount of algae, while adding some natural stability to my system. Any thoughts here?

 

[Water Dog]

Don’t be in such a rush to starve your system of nutrients. Your current levels of NO3 at 5 and PO4 at .037 is fine. What you don’t want to do is drive everything to zero, starve your coral and have a nutrient limited tank that is a perfect environment for dinoflagellates to rear their ugly head.

 

[Daniel92481]

Yes, this is what I’m afraid of. I currently do a 5 gallon water change every week that is really inconvenient. By the next Friday, my nitrates rise to 10. I was hoping with the refugium, I could do bi weekly 5 gallon changes. This would also give the chaeto nutrients to grow and rid my tank of small patches of green algae. What do you think?