STN..... why??

Scott07 · 07/25/2018, 09:34 AM

I'd like to think I've come a long way from my early attempts at keeping SPS. I monitor alk daily, keep my nutrients low, and do weekly water changes religiously. But for the past several months (not sure precisely how long) I've been dealing with STN on some of my SPS. I'll post parameters below since I know that'll be everyone's first question. Recent changes include a new replacement mp10 wet side. I replaced this several months ago and if memory serves me a few weeks or maybe a month before the stn started. Normally i would never suspect this except that there was a pea sized gob of lubricant on the new propeller shaft that killed my skimmer for a week or so. I also recently switched from black diamond marineland carbon to aquafx small pellets that appear similar to brs rox. I run this and a small amount of gfo in a media bag in my sump continuously. I switched carbon after the stn had started however. I've also been adding small amounts of dry, washed sand over the last few water changes, but again long after i first started seeing stn.

The STN I'm seeing is selective. Some sps are affected and having tissue receed from the base. Others are growing, and my alk/ calcium consumption is actually on par with what it was before the stn started. Smooth skinned acros were affected first, but now a small frag of ora borealis which was encrusting onto the rock is affected as well. Other branching acros; a tri color, a rainbow stylo colony, two types of birdsnest, etc are growing.

I'm thinking about discontinuing gfo, but I'm not sure what else to try. Any help or direction is greatly appreciated! I'll try to answer questions as quickly as i can.

Parameters (65 gallon display plus sump):

-Alk: 8.3dkh (salifert)(drifts between 8.1 and 8.3 or so throughout the week)
-Calcium: 440ppm (red sea)
-Mg: 1300 (red sea)
-Nitrate: 0 (api)
-Phosphate: 0.00 (hanna phosphate, NOT ulr checker). My phosphate can't be zero as I have to clean a good bit of dust algae off my glass daily, but my cheato does not grow much either).
-Salinity: 1.025 (refractometer calibrated each use with solution)

Scott07 · 07/25/2018, 11:15 AM

Just finished my 16gal. weekly water change. I removed gfo, and added fresh carbon. I inspected all pumps, powerheads, and heaters as well as i could, without removing them, for rust. I didn't find any. I guess i can pick up a poly filter soon and try to rule out contaminants. Anything I'm not thinking of?

Greg 45 · 07/25/2018, 03:16 PM

I was in the same boat stop chasing numbers and feed the tank. Whey the corals look happy then check numbers and stay close to that reading.

Scott07 · 07/25/2018, 04:39 PM

Quote:

Originally Posted by Greg 45

I was in the same boat stop chasing numbers and feed the tank. Whey the corals look happy then check numbers and stay close to that reading.

Thanks, I'm going to start feeding frozen daily instead of every other day and stop running gfo. Hopefully it's that simple.

Tripod1404 · 07/25/2018, 06:38 PM

I would remove GFO and carbon. Imo GFO is the main cause of STN in SPS as it strips water of phosphate. Most of the explainable causes of STN can be attributed to unnecessary/excessive levels of nutrient reduction. Also 0 nitrate is not a good thing. It is doable(assuming its actually very low but not zero) with low alk around NSW levels, but SPS are much more hardy with 1-3 ppm nitrate. You might need to dose nitrate to get it there, if it doesn't climb on its own.

I would bet, if you remove GFO, you SPS will eventually recover. I also had much better color after I stopped using carbon, but this might be something I imagine

. At least nothing got worse until I removed carbon and I no longer need to buy activated carbon.

Scott07 · 07/25/2018, 07:32 PM

Dosing nitrate is something I've considered before as I've never been able to get a reading of more than 0. I don't want to change too much too fast, but I will continue to consider it if I can't get nitrates up with increased feeding. I guess first step would be buying a better test kit.

StarF · 07/26/2018, 03:46 AM

anything lower than:
no3 2-5 and po4 0,025 - 0,05 and my acropora starts to show sign off stn..

Anemone · 07/31/2018, 12:16 AM

Quote:

Originally Posted by StarF

anything lower than:
no3 2-5 and po4 0,025 - 0,05 and my acropora starts to show sign off stn..

This. I don't think you need to dose Nitrate, but you might need to dose phosphate. You'll get plenty of Nitrate from daily feedings, but phosphate isn't as easy. Zero on either (or both), is basically starving your SPS and will lead to STN.

Good luck,
Kevin

Scott07 · 07/31/2018, 06:22 AM

Thank you all for the help so far. STN has slowed to barely noticeable and I'm hoping will stop entirely soon. I picked up a red sea nitrate pro kit to measure my nitrates with better resolution. Even on this kit I'm still getting 0.00ppm. Agreed that I think I'm going to stay away from dosing nitrates if i don't have to, but I would like to see more than a zero reading.

My current plan is to continue increased feeding, and also maintain my water changes etc... to avoid swinging too far too fast and dealing with an algae outbreak. Hopefully all corals with stn will pull through!

Tripod1404 · 07/31/2018, 10:14 AM

Quote:

Originally Posted by Anemone

This. I don't think you need to dose Nitrate, but you might need to dose phosphate. You'll get plenty of Nitrate from daily feedings, but phosphate isn't as easy. Zero on either (or both), is basically starving your SPS and will lead to STN.

Good luck,
Kevin

I cannot increase nitrate by feeding more, only dosing nitrate works. But I can easily raise phosphates by feeding more. Its probably tank/biofilter dependent.

Anemone · 07/31/2018, 09:36 PM

Quote:

Originally Posted by Tripod1404

I cannot increase nitrate by feeding more, only dosing nitrate works. But I can easily raise phosphates by feeding more. Its probably tank/biofilter dependent.

Interesting. The ratio of nitrates to phosphates in foods is fairly heavily weighted in favor of nitrates (as the end product of ammonia/nitrite decomposition). Are you dosing (or using) a carbon based biofilter?

Kevin

Tripod1404 · 08/01/2018, 12:22 AM

Quote:

Originally Posted by Anemone

Interesting. The ratio of nitrates to phosphates in foods is fairly heavily weighted in favor of nitrates (as the end product of ammonia/nitrite decomposition). Are you dosing (or using) a carbon based biofilter?

Kevin

Nope, I don’t dose any liquid carbon. I also don’t use gfo, carbon or any other absorption media. I have chaeto in fuge, but that is mainly for breeding copepods. I don’t harvest it until it overgrows it’s compartment.

I do have an oversized skimmer. It’s true that foods are richer in nitrogen. But most of that is locked in amino acids and skimmer can remove at least some of that. Phosphate much less skimmable.

jda · 08/01/2018, 08:33 AM

Just feed the fish a lot. A number of a test kit means nothing... it is throughput that matters. For example, a tank with 12 fish, but N of .1 and P of .005 has more building blocks floating through it than a tank with 1 fish and the same numbers. I think that with the advent of good test kits, people have started to chase numbers and forgot that heavy import and heavy export is what is important.

I would stop the GFO for sure. GFO can be really helpful, but having some P is not really an issue. Your water changes should keep it mostly under control if you keep on skimming heavy. If it starts to climb, then natural control like a fuge or chaeto reactor can be really helpful since it can never strip you to zero like media can.

Do you have point-source LEDs? If so, then some base STN can happen as the grow with the shadowing. This does not feel right after reading your posts, but it is the only other thing that I could come up with.

07/25/2018, 09:34 AM	#1
Scott07 Registered Member Join Date: Oct 2013 Location: Pittsburgh, PA Posts: 384	STN..... why?? I'd like to think I've come a long way from my early attempts at keeping SPS. I monitor alk daily, keep my nutrients low, and do weekly water changes religiously. But for the past several months (not sure precisely how long) I've been dealing with STN on some of my SPS. I'll post parameters below since I know that'll be everyone's first question. Recent changes include a new replacement mp10 wet side. I replaced this several months ago and if memory serves me a few weeks or maybe a month before the stn started. Normally i would never suspect this except that there was a pea sized gob of lubricant on the new propeller shaft that killed my skimmer for a week or so. I also recently switched from black diamond marineland carbon to aquafx small pellets that appear similar to brs rox. I run this and a small amount of gfo in a media bag in my sump continuously. I switched carbon after the stn had started however. I've also been adding small amounts of dry, washed sand over the last few water changes, but again long after i first started seeing stn. The STN I'm seeing is selective. Some sps are affected and having tissue receed from the base. Others are growing, and my alk/ calcium consumption is actually on par with what it was before the stn started. Smooth skinned acros were affected first, but now a small frag of ora borealis which was encrusting onto the rock is affected as well. Other branching acros; a tri color, a rainbow stylo colony, two types of birdsnest, etc are growing. I'm thinking about discontinuing gfo, but I'm not sure what else to try. Any help or direction is greatly appreciated! I'll try to answer questions as quickly as i can. Parameters (65 gallon display plus sump): -Alk: 8.3dkh (salifert)(drifts between 8.1 and 8.3 or so throughout the week) -Calcium: 440ppm (red sea) -Mg: 1300 (red sea) -Nitrate: 0 (api) -Phosphate: 0.00 (hanna phosphate, NOT ulr checker). My phosphate can't be zero as I have to clean a good bit of dust algae off my glass daily, but my cheato does not grow much either). -Salinity: 1.025 (refractometer calibrated each use with solution) __________________ 65 gallon mixed reef Good maintainence and husbandry is a cumulative effect, not a single event.

07/25/2018, 11:15 AM	#2
Scott07 Registered Member Join Date: Oct 2013 Location: Pittsburgh, PA Posts: 384	Just finished my 16gal. weekly water change. I removed gfo, and added fresh carbon. I inspected all pumps, powerheads, and heaters as well as i could, without removing them, for rust. I didn't find any. I guess i can pick up a poly filter soon and try to rule out contaminants. Anything I'm not thinking of? __________________ 65 gallon mixed reef Good maintainence and husbandry is a cumulative effect, not a single event.

07/25/2018, 06:38 PM	#5
Tripod1404 Registered Member Join Date: Mar 2016 Posts: 1,821	I would remove GFO and carbon. Imo GFO is the main cause of STN in SPS as it strips water of phosphate. Most of the explainable causes of STN can be attributed to unnecessary/excessive levels of nutrient reduction. Also 0 nitrate is not a good thing. It is doable(assuming its actually very low but not zero) with low alk around NSW levels, but SPS are much more hardy with 1-3 ppm nitrate. You might need to dose nitrate to get it there, if it doesn't climb on its own. I would bet, if you remove GFO, you SPS will eventually recover. I also had much better color after I stopped using carbon, but this might be something I imagine . At least nothing got worse until I removed carbon and I no longer need to buy activated carbon. Last edited by Tripod1404; 07/25/2018 at 06:45 PM.

07/25/2018, 07:32 PM	#6
Scott07 Registered Member Join Date: Oct 2013 Location: Pittsburgh, PA Posts: 384	Dosing nitrate is something I've considered before as I've never been able to get a reading of more than 0. I don't want to change too much too fast, but I will continue to consider it if I can't get nitrates up with increased feeding. I guess first step would be buying a better test kit. __________________ 65 gallon mixed reef Good maintainence and husbandry is a cumulative effect, not a single event.

07/31/2018, 06:22 AM	#9
Scott07 Registered Member Join Date: Oct 2013 Location: Pittsburgh, PA Posts: 384	Thank you all for the help so far. STN has slowed to barely noticeable and I'm hoping will stop entirely soon. I picked up a red sea nitrate pro kit to measure my nitrates with better resolution. Even on this kit I'm still getting 0.00ppm. Agreed that I think I'm going to stay away from dosing nitrates if i don't have to, but I would like to see more than a zero reading. My current plan is to continue increased feeding, and also maintain my water changes etc... to avoid swinging too far too fast and dealing with an algae outbreak. Hopefully all corals with stn will pull through! __________________ 65 gallon mixed reef Good maintainence and husbandry is a cumulative effect, not a single event.

07/25/2018, 03:16 PM	#3
Greg 45 Registered Member Join Date: Aug 2005 Location: Bayonne,N.J. Posts: 1,159	I was in the same boat stop chasing numbers and feed the tank. Whey the corals look happy then check numbers and stay close to that reading.

07/26/2018, 03:46 AM	#7
StarF Registered Member Join Date: Jan 2008 Location: Denmark Posts: 586	anything lower than: no3 2-5 and po4 0,025 - 0,05 and my acropora starts to show sign off stn..

08/01/2018, 08:33 AM	#13
jda Dogmatic Dinosaur Join Date: Feb 2004 Location: Boulder, CO Posts: 6,256	Just feed the fish a lot. A number of a test kit means nothing... it is throughput that matters. For example, a tank with 12 fish, but N of .1 and P of .005 has more building blocks floating through it than a tank with 1 fish and the same numbers. I think that with the advent of good test kits, people have started to chase numbers and forgot that heavy import and heavy export is what is important. I would stop the GFO for sure. GFO can be really helpful, but having some P is not really an issue. Your water changes should keep it mostly under control if you keep on skimming heavy. If it starts to climb, then natural control like a fuge or chaeto reactor can be really helpful since it can never strip you to zero like media can. Do you have point-source LEDs? If so, then some base STN can happen as the grow with the shadowing. This does not feel right after reading your posts, but it is the only other thing that I could come up with.