SPS do not like GFO no matter the amount

[ocncheffy]

So I’ve been trying to utilize GFO in a reactor with carbon to bring down my phosphate levels from .35 to .15. I’ve picked up some Rowaphos and using half the amount, it dropped to .25 in a weeks time. Did another round and dropped it to .15 successfully. The problem appears with some of my SPS seem to get burnt tips, and two rather new wild Acro colonies have completely RTN’d.

I’ve had this issue in the past and avoided GFO but then of course phosphate levels rose and growth seemed to slow down. I’m stumped to why this is an issue in my tank when others run much lower phosphate levels with GFO successfully. LPS have no issues. Do I maybe need to lower alk to 7.0 to curb burnt tips/RTN? I’ve heard some tanks just need to run lower alkalinity.

Current Parameters:
Alk-7.6
Nitrate-20
Phosphate-.15
Mag-1320
Calcium-420
PH - swings from 7.95-8.2

Average PAR for my SPS is around 250, lit with dual XR30 G5’s at 55%. I’ll attach my lighting schedule and percentages as well.

 

[Manny’s Reef]

I’ve always used GFO with SPS no problem. Check out the channel Coral Euphoria. Some of the nicest SPS you’ll see and he runs GFO. Don’t think it’s directly tied to GFO.

 

[BirdFish5000]

I've had 100% the same issues. I've been even used GFO at as little as 10% of the recommended amount, changing every single day to avoid swings, and still run into issues.

Presently running an algae scrubber. My po4 numbers are coming down <extremely> slowly, but the tank looks far better, and the acro frags aren't complaining like they would with GFO.

 

[ocncheffy]

I didn’t think a week to drop from .35 to .25 was too fast. Maybe I’m wrong? But it sounds like I’m having the exact issue as above.

 

[BirdFish5000]

.35 to .25 over a week is actually pretty fast, imo

 

[Rams]

Same for me..ever since I removed gfo I see better growth and coloration

 

[brandon429]

you need to reduce light levels accordingly, a breakpoint happens between sunburning and various tissue insult moves we do to sps

you'll reduce losses greatly if you bring down light intensity for about eight weeks and ramp up slowly once you cease use of it/other irritants.

 

[Miami Reef]

@Randy Holmes-Farley

Some people use GFO with SPS with no ill effects, while others appear to have death with it. I read this thread you made a while ago, and I feel like it really applies to here.

Reefers may over-rely on personal experience to accept or reject truth

OK, I know that's a provocative title, but hear me out. From many, many discussions I have had with reefers over the past 25 years, it is clear to me that many folks easily accept ideas that mesh with their experience, and strongly reject those that do not. Unfortunately, this reliance on...

www.reef2reef.com

 

[fryman]

0.35 ppm is high but not an emergency. 0.15 and lower would be ok but I've had issues when phophate level changes quickly. GFO also absorbs other elements so it's not necessarily the phosphate level that stressed your SPS.

Basically I think you added too much GFO too quickly. Happens alot, I think. I've done it too.

 

[BirdFish5000]

It's shockingly easy to do. The recommended amounts (on the labels, and BRS calculator) are WAY off, imo

 

[ocncheffy]

you need to reduce light levels accordingly, a breakpoint happens between sunburning and various tissue insult moves we do to sps

you'll reduce losses greatly if you bring down light intensity for about eight weeks and ramp up slowly once you cease use of it/other irritants.

This is interesting. I’ve never through to reduce my lighting when dropping phosphates. Maybe I’ll cut my dose in half, then run an acclimation mode for 2 weeks.

 

[t5Nitro]

My sps aren't a fan either. Look worse every time a new bag of gfo is added for a period of time.

 

[brandon429]

our sand rinse thread where we rip out 100% of the waste from a reef tank in one pass, I'm talking full disassembly surgery for tank moves/transfers/sandbed swaps used to get bleaching corals until we started the light ramping then it cured it 100% eighth year running bc the keepers stop raising the reset level if the coloration doesn't hold relative to their feed consistency and quality in the new ripped clean tank.

lets us find the new max setpoint, I'm sure alk and phos and other interplays are happening all together, seems to really be helping our big tank surgery thread, we really rely on it to prevent killing people's $ system when doing various jobs

some kind of steady state develops in high par settings where provided health is in place, the coral machinery/color system holds and tissue grows

but rob 100% of the organics that leak a little nutrients into the tank all in one pass, keep the same sun burn level/bleaching was a real concern

treating those rip clean systems as new LED light owners/ramp up slowly literally removed the bleaching issue completely and we do picos, nanos, full size tanks in the transfer thread, a few 300 gallon tank transfers, probably 500 completed jobs so far with the light ramping. such a harmless easy thing to try/won't hurt any system even if we did it without a need. merely a cloudy spell on the reef for a while

 

[homer1475]

I use GFO with an SPS dominate system, no issues.

Whats recommended and what I actually use are 2 totally different thing.

To drop my phosphates from .3 to .1 takes about a month. I only use 3tbs of GFO mixed with carbon changed every other week. 85 gallon total system.

It's very easy to over use GFO, and dropping .1 in a week is to fast IMO.

 

[taricha]

This is interesting. I’ve never through to reduce my lighting when dropping phosphates.

Definitely an idea worth considering. There was a long discussion thread about light alkalinity and nutrients with an emphasis on SPS. What I took away from it was that systems can be successful at high or low values of any of those 3 factors, but there was clear interconnection between them. People with a lot of experience knew that certain combinations would cause stress responses in their sps. (Stuff like having to keep the alkalinity down much lower if you ran strong lighting and low po4.)

 

[The Opinionated Reefer]

The issue is that your SPS become used to high phosphates and when you try to lower them it causes stress and STN. If you grow an Acro in high phosphates then it should stay in a higher phosphate environment. It's fine to go from low phosphates to high phosphates, that won't kill anything but when you try to go the opposite way it will cause the issues you mentioned.

@Hans-Werner has discussed this issue with me in the past.

 

[Koty]

I would combine GFO with carbon dosing. TM has a lot to say about it