SPS and GFO

[RCS82]

Hello all. Thought I would post here so all you sps fanatics can chime in as I really appreciate all the great info in this group. Just looking for thoughts, opinions or just a general consensus on using gfo with sps and if anyone was seeing positive results or negative. Maybe people are running gfo and carbon with success or just carbon alone.
Just hoping everyone will throw in their 2 cents on running gfo or gfo/carbon with sps dominant tanks.
Thanks a bunch.

 

[ndrwater]

GFO works wonders with removing ohosphaph from our tanks, but... It can work to we'll sometimes too. A ballance of Nitrate and Phosphate is best when keeping SPS

 

[RCS82]

Thanks for the reply. I've been using gfo off and on for a couple years on my tank which is becoming sps dominant I would say. Been having reasonably good success but still feel there is a couple hurdles left and was mainly wondering if gfo was one of these hurdles.

 

[ndrwater]

I took the gfo offline several years ago when the phosphates Leaching from the rocks tapered off. No Ill affects whatsoever

 

[bubbaque]

GFO works great for keeping phosphate in a good range if you can’t do it but a more natural means like growing chaeto. It is something you need to be more cautious as it can strip phosphate too low.

 

[Charlie’s Frags]

I had nothing but negative results from using gfo and carbon dosing. I soon as I got rid of them and stopped chasing low nutrients my sps began to survive. I maybe of guilty of not using it correctly but every acro I bought during that time would survive for a couple weeks then stn or rtn. As soon as I got rid of them my acros started growing like crazy with amazing colors and polyp extension. I still have a skimmer and grow a little chaeto in a small diy reactor and my nutrients are lower now than before and stable. When I had gfo my po4 would fluctuate between 0 and 0.3 and my nitrates were even more sporadic. They would be 25-50 then down to 5 the next day and back to 20,etc. Now the no3 is rock solid 1-2 and po4 stays 0.03-0.05. I actually dose no3 and po4 a couple times a week now.

 

[jda]

IMO, GFO is not an issue, but the application can be. I would not use it on a newish tank (less than a year) - there are microfauna and bacteria that need to grow and they don't need chemical interference. If you do use it on an established tank, then it needs to be applied very slowly so that levels to not drop too fast.

If you have a good amount of P in the water, then your rocks and sand will have bound up too. Read up on aragonite binding phosphate - in a nutshell, it bind to equilibrium with the water around it... the more in the water, the more it will hold. It is important to understand this. Once you remove some of the P in the water with GFO, the aragonite will release some and you will quickly have the levels bounce back up once the GFO is removed or exhausted. Basicaly, if you go too fast, you can lower quickly and then raise quickly - this is a big issue to most.

GFO can unbind P if you use it water with a lower concentration. Always change it when you change water.

GFO can also get covered in organics quite quickly, so putting a bunch in a reactor can be wasteful if it is in the tank for a while... smaller amounts changed more frequently seems best for both slow application but also to keep organics from rendering it useless.

 

[Charlie’s Frags]

IMO, GFO is not an issue, but the application can be. I would not use it on a newish tank (less than a year) - there are microfauna and bacteria that need to grow and they don't need chemical interference. If you do use it on an established tank, then it needs to be applied very slowly so that levels to not drop too fast.

If you have a good amount of P in the water, then your rocks and sand will have bound up too. Read up on aragonite binding phosphate - in a nutshell, it bind to equilibrium with the water around it... the more in the water, the more it will hold. It is important to understand this. Once you remove some of the P in the water with GFO, the aragonite will release some and you will quickly have the levels bounce back up once the GFO is removed or exhausted. Basicaly, if you go too fast, you can lower quickly and then raise quickly - this is a big issue to most.

GFO can unbind P if you use it water with a lower concentration. Always change it when you change water.

GFO can also get covered in organics quite quickly, so putting a bunch in a reactor can be wasteful if it is in the tank for a while... smaller amounts changed more frequently seems best for both slow application but also to keep organics from rendering it useless.

Great input as usual, but that doesn’t change my opinion on gfo or carbon dosing. If any product is that sensitive with a margin of error that small it’s not for me. I’ve talked with many high end sps dealers, collectors and vendors and none of them recommend gfo. It didn’t have any negative effects on zoas or my lps but it crippled my sps. Adding the fact that my tank specifically did a 180 within 7-10 days after I discontinued these types of products convinced me that I don’t need them.

 

[RCS82]

Great responses and thanks. My 90 gallon is definitely heavy on rock work, which I like, and was started with all dry rock. But it is well established and going on 3 years old. When I do use gfo I never use a whole lot either. I definitely dont have much to complain about. Just wanted a bit of discussion on running gfo with sps.
Attached is a fairly recent Fts.
Thanks again

 

[NS Mike D]

Great input as usual, but that doesn’t change my opinion on gfo or carbon dosing. If any product is that sensitive with a margin of error that small it’s not for me. I’ve talked with many high end sps dealers, collectors and vendors and none of them recommend gfo. It didn’t have any negative effects on zoas or my lps but it crippled my sps. Adding the fact that my tank specifically did a 180 within 7-10 days after I discontinued these types of products convinced me that I don’t need them.

Why would anyone recommend GFO for the sake of merely using GFO? IMO, the only reason to use GFO is if you NEED to remove PO4 from your tank. FWIW, a sps dealer, vendor etc is running a tank much different that the home display tank. They aren't stocking their tanks with pet fish and thus adding a lot of food to those tanks. They add just enough fish (often only one) to supply the tank with just the right amount of NO3 and PO4 for their corals. So if a dealer/vendor/etc is using GFO, I would question what is he/she doing that he/she has excess PO4.

Remember that corals need NO3 and PO4 and if you are using GFO leaving little to no PO4, other nuisance algae/bacteria will thrive while corals suffer.

full disclosure, I run GFO and changed it today. Why. because my tank and testing confirm the use. The cyano on my sand bed is telling me that what my Red Sea test kits confirms, that my PO4 is 0.08ppm and that is the upper limit of my target range. NO3 is 0.1 which is a bit low. Thus my tank would benefit from some extra coral feeding and lowering of PO4 by use of GFO. My LPS and SPS are happy. I am sure if I didn't measure PO$ and temper my use of GFO to keep PO4 within my target ranges, the LPS and SPS would be quick to let me know.

as for carbon dosing and GFO, carbon dosing can take NO3 down too fast in the beginning - thus it's recommended that one start slowly with carbon dosing and if NO3 drops with PO4 dropping, GFO can help keep them in balance. But once carbon dosing had reached a desired equilibrium, there should be no need to use GFO.

 

[ReefyB]

I’ve been running GFO and carbon, both in their own reactors since my tank was setup, and it’s only about 5 months old at this point. Small 45g sps dominant system with about ten acro frags all encrusting very nicely (the first ones I added when the tank was only 2 months, and they’ve already encrusted well beyond the plugs and onto my rock). Personally I think running GFO at the start is a great for reducing all the crap that leeches from rock/sand in a new system. Despite running GFO and carbon 24/7, I still had a brief cyano phase, followed by a tiny bit of bubble algae and hair algae... but I’m talking so little that most wouldn’t even notice it unless you stared at the tank everyday. Now, all the bad algae is practically gone, even though I just ordered a fuge light because I was going to setup some macroalgae to help prevent any of the bad algae from spreading. Light gets here tomorrow but I’m worried that my phosphates are finally beginning to drop (it’s always read 0 on testing, but since I had algae I knew it was just being absorbed), so the added macro with my GFO could become overkill which may cause issues down the road. I think I’ll just stick with the GFO for now, if it ain’t broke don’t fix it as they say.

 

[NS Mike D]

I’ve been running GFO and carbon, both in their own reactors since my tank was setup, and it’s only about 5 months old at this point. Small 45g sps dominant system with about ten acro frags all encrusting very nicely (the first ones I added when the tank was only 2 months, and they’ve already encrusted well beyond the plugs and onto my rock). Personally I think running GFO at the start is a great for reducing all the crap that leeches from rock/sand in a new system. Despite running GFO and carbon 24/7, I still had a brief cyano phase, followed by a tiny bit of bubble algae and hair algae... but I’m talking so little that most wouldn’t even notice it unless you stared at the tank everyday. Now, all the bad algae is practically gone, even though I just ordered a fuge light because I was going to setup some macroalgae to help prevent any of the bad algae from spreading. Light gets here tomorrow but I’m worried that my phosphates are finally beginning to drop (it’s always read 0 on testing, but since I had algae I knew it was just being absorbed), so the added macro with my GFO could become overkill which may cause issues down the road. I think I’ll just stick with the GFO for now, if it ain’t broke don’t fix it as they say.

what test kit are you using? If API, then note that their NO3 & PO4 tests are not sufficiently sensitive for reef tanks. zero is bad and your corals will suffer. When corals can't grow there are nuisance algae and bacteria more that happy to move in that nutrient dessert and make use of whatever they can.

If your tests are accurate, the running GFO to keep PO4 at zero is starving your corals of an essential compound.

 

[NS Mike D]

Great responses and thanks. My 90 gallon is definitely heavy on rock work, which I like, and was started with all dry rock. But it is well established and going on 3 years old. When I do use gfo I never use a whole lot either. I definitely dont have much to complain about. Just wanted a bit of discussion on running gfo with sps.
Attached is a fairly recent Fts.
Thanks again

nice tank

 

[RCS82]

Thanks.
I've never used large quantities of gfo and have never stripped my tank of PO4. My tank can get up to .15 usually and I add a little rowaphos in a reactor for a couple weeks and it gets down to .05 or .08. Nuisance algea hasn't been a big problem either so like I said earlier nothing really to complain about. I dont have the room for a nice fuge so gfo is kinda it for me. Glad to hear some real sps opinions on gfo.

 

[ReefyB]

what test kit are you using? If API, then note that their NO3 & PO4 tests are not sufficiently sensitive for reef tanks. zero is bad and your corals will suffer. When corals can't grow there are nuisance algae and bacteria more that happy to move in that nutrient dessert and make use of whatever they can.

If your tests are accurate, the running GFO to keep PO4 at zero is starving your corals of an essential compound.

Nyos for Nitrate, and both Salifert / Hanna for phosphate. My nitrates are around 10-12. For phosphates, Hanna showed above zero months ago, I’ve just been using Salifert lately which shows zero. Like I mentioned, I don’t think PO4 is actually at zero, since my SPS is growing so well and previously I had some bad algae.. but now with that algae gone, I’m wondering if it is beginning to actually zero out. I’ll test it on Hanna again and see what I get.

 

[jda]

I can have 30 ppb on the Hannah Ultra Low and still show "clear" on Salifert phosphate. I would just treat the Salifert as a swag where "no color" is low and then go up from there based on the little card.

Unless you are using a massive amount of GFO, organic carbon or LC, then there is no possible way that your P is truly at zero. Even 1 or 2 PPB are not growth limiting to acropora.

 

[Charlie’s Frags]

Why would anyone recommend GFO for the sake of merely using GFO? IMO, the only reason to use GFO is if you NEED to remove PO4 from your tank. FWIW, a sps dealer, vendor etc is running a tank much different that the home display tank. They aren't stocking their tanks with pet fish and thus adding a lot of food to those tanks. They add just enough fish (often only one) to supply the tank with just the right amount of NO3 and PO4 for their corals. So if a dealer/vendor/etc is using GFO, I would question what is he/she doing that he/she has excess PO4.

Remember that corals need NO3 and PO4 and if you are using GFO leaving little to no PO4, other nuisance algae/bacteria will thrive while corals suffer.

full disclosure, I run GFO and changed it today. Why. because my tank and testing confirm the use. The cyano on my sand bed is telling me that what my Red Sea test kits confirms, that my PO4 is 0.08ppm and that is the upper limit of my target range. NO3 is 0.1 which is a bit low. Thus my tank would benefit from some extra coral feeding and lowering of PO4 by use of GFO. My LPS and SPS are happy. I am sure if I didn't measure PO$ and temper my use of GFO to keep PO4 within my target ranges, the LPS and SPS would be quick to let me know.

as for carbon dosing and GFO, carbon dosing can take NO3 down too fast in the beginning - thus it's recommended that one start slowly with carbon dosing and if NO3 drops with PO4 dropping, GFO can help keep them in balance. But once carbon dosing had reached a desired equilibrium, there should be no need to use GFO.

I totally agree. You and JDA’s input made me realize that I didn’t articulate my position/experience correctly. A year ago I was committing involuntary coralslaughter because I read, and was told so many times, that acros grow faster and show better color when nitrates are x and phosphates are y, so that’s what I tried to achieve. But I’ve learned, atleast in my tank, that my sps do better with phosphates at 0.2 than they do at 0.02 because of gfo. It’s weird/crazy that my nutrients are now lower than what I was chasing with gfo and carbon dosing.
What I’m trying to say is if your po4 measures 0.10 don’t freak out and try to drive them down to 0.02 over night with gfo. Chasing 0.02 with gfo caused me way more problems and acrocide than just leaving them at 0.10 would of done.

 

[jda]

Chasing numbers is not good - for sure. However, if you need to lower P, then GFO is fine if you are smart and slow. Most people mess up because they are chasing, do not understand how to use it or do not understand how the aragonite is both working for, and against, them depending on the levels and goals. This is complicated, for sure, but if you want to be successful, then you have to understand.

More about aragonite binding of phosphate... when you get fresh live rock or sand (from the ocean) is is mostly phosphate free since the reefs are very low levels of phoshate and rock has given up all the phosphate that it has. Early on in a new tank, the rock can bind up all free phosphate in the water and leave your test kit showing VERY low or at zero. This takes a few months, or more, to bind up enough so that there is some left in the water. On a normal tank, this can happen along with the cycle and early phases of the tank and it is no issue since by the time that you are ready to add coral there is enough bound up in the rock to leave a trace for the coral and other inhabitants. In this case, the aragonite can act like a buffer absorbing a bit more in between water changes and releasing some when the water gets too low - this is good and healthy. When people use GFO, LC and Organic Carbon from the start, they do not allow the rock to bind up during the early stages and it has to do it later on. It is good to be patient with a new tank and let nature work.

Dry rock has also thrown a wrench in all of this since it is nearly always bound with some terrestrial phosphate and sometimes it has A LOT. Treatments to remove this in the tank can sometimes strip the water too clean in order to get the rock to release as much P as possible to growth-limit the algae - this is the scenario that you see with VERY low residual P levels, but hair algae all over the rocks. This can grow-limit the corals by denying them building blocks. I used to caution people to avoid dry rock at all costs, since the costs over the first few years of ownership can dwarf the cost of real phosphate-free rock, but without a good current source of real pacific rock, I don't know what to do now.

While I do totally believe that acropora (not so much other corals) do grow and color better with very low, but detectable, building blocks (along with lots of food from the zoox from high quality lighting), I would not recommend this until a tank is REALLY stable - most people on this board might not have a tank old enough to be here which sometimes requires 2-3 years of being set up.

 

[Charlie’s Frags]

Chasing numbers is not good - for sure. However, if you need to lower P, then GFO is fine if you are smart and slow. Most people mess up because they are chasing, do not understand how to use it or do not understand how the aragonite is both working for, and against, them depending on the levels and goals. This is complicated, for sure, but if you want to be successful, then you have to understand.

More about aragonite binding of phosphate... when you get fresh live rock or sand (from the ocean) is is mostly phosphate free since the reefs are very low levels of phoshate and rock has given up all the phosphate that it has. Early on in a new tank, the rock can bind up all free phosphate in the water and leave your test kit showing VERY low or at zero. This takes a few months, or more, to bind up enough so that there is some left in the water. On a normal tank, this can happen along with the cycle and early phases of the tank and it is no issue since by the time that you are ready to add coral there is enough bound up in the rock to leave a trace for the coral and other inhabitants. In this case, the aragonite can act like a buffer absorbing a bit more in between water changes and releasing some when the water gets too low - this is good and healthy. When people use GFO, LC and Organic Carbon from the start, they do not allow the rock to bind up during the early stages and it has to do it later on. It is good to be patient with a new tank and let nature work.

Dry rock has also thrown a wrench in all of this since it is nearly always bound with some terrestrial phosphate and sometimes it has A LOT. Treatments to remove this in the tank can sometimes strip the water too clean in order to get the rock to release as much P as possible to growth-limit the algae - this is the scenario that you see with VERY low residual P levels, but hair algae all over the rocks. This can grow-limit the corals by denying them building blocks. I used to caution people to avoid dry rock at all costs, since the costs over the first few years of ownership can dwarf the cost of real phosphate-free rock, but without a good current source of real pacific rock, I don't know what to do now.

While I do totally believe that acropora (not so much other corals) do grow and color better with very low, but detectable, building blocks (along with lots of food from the zoox from high quality lighting), I would not recommend this until a tank is REALLY stable - most people on this board might not have a tank old enough to be here which sometimes requires 2-3 years of being set up.

What’s the benefit of feeding “sps” specific food? If all they need is detectable building blocks then why not just dose a little nitrate and phosphate and skip the nitrogen phase?

 

[lapin]

Just food for thought
https://www.advancedaquarist.com/2012/2/chemistry