GFO and tissue striping, possible causes?

[FranklinDattein]

Hi fellow chemist enthusiasts,

for a long time I have been struggling with GFO, as every time I use it, SPS starts to lose tissue rapidly.

I wondering if there is any reasonable explanation from a chemistry point of view.

I have ruled out the hypothesis it is caused by rapid decrease in PO4. Every year I do a large water change of around 90% , which brings PO4 down with no side effects.

Some goes for the hypothesis of an alk swing, as I run a monitor and I did set it to test every hour, in the two days following the addition of GFO.

additionally, I do ICP every 4 months and there is never anything too high. Sometimes some elements are on the low, like boron, fluoride, potassium and strontium but the tank goes fine with that.

Any other ideas?


Also, I have tested several combinations of amount and flow in the reactor, and the tissue striping doesn’t happen if go slow. The problem is that is had to be too slow, enough to not make a dent on the phosphate.

I have been monitoring it and having the same bad results with a range between 0.1 to 0.6ppm, over the years. So, it is not that it is close to depletion either.

I’ve also tested 3 different brands of GFO with equal results. (Rowa, salifert, Aquaforest)

The alternative aluminum oxide doesn’t seem to have the same side effect, but slowly accumulates aluminumium which has been a problem in the past.

for context, it is a 500l tank packed to the brim with SPS.

 

[Reefering1]

Maybe use less gfo

 

[arking_mark]

Is an issue with the tank that requires PO4 reduction?

 

[Pod_01]

I definitely seen SPS loose the tissue when PO4 is sinking and sinking permanently with GFO. Water change is temporary decrease, PO4 will leach out of the rock and be back to the original level. I observed especially bad effects when going from 0.07 to 0.02 and with GFO. At levels above 0.1 going up or down I observed nothing but I also do not use GFO.
Reading up on Florine I found this:

Maybe you have interactions of few issues. Together they cause problem but alone all is good.

Good luck

 

[arking_mark]

I'm asking why you are trying to reduce PO4 if it's impacting otherwise healthy coral? Is the PO4 level causing issues and that's why you're trying to reduce it with GFO?

 

[archercorals]

There is something else off for gfo to cause this. 1000s of ppl use gfo in sps tanks with no issues.

 

[FranklinDattein]

There is something else off for gfo to cause this. 1000s of ppl use gfo in sps tanks with no issues.

I agree, but there is also hundreds of people on this forum and elsewhere reporting the tissue striping symptoms.

I'm asking why you are trying to reduce PO4 if it's impacting otherwise healthy coral? Is the PO4 level causing issues and that's why you're trying to reduce it with GFO?

Not currently, but if it continues raising at this pace I might not be able to get away with it anymore. It went from 0.16 to 0.74ppm in two years.

Maybe you have interactions of few issues. Together they cause problem but alone all is good.

Good luck

That rings a bell as Fluorine has been on the low and the tissue striping usually starts from the bottom. Thanks for sharing.
This hypothesis also fits the narrative that there might be an extra component aggravating the issue, which would explain why some GFO users do have the problem and some don't.

As for the PO4 leeching from rocks and substrate, I would say that the same goes for any export method, including GFO and water changes. Thoughts?


Thanks all for sharing your thoughts.

 

[Randy Holmes-Farley]

I have ruled out the hypothesis it is caused by rapid decrease in PO4. Every year I do a large water change of around 90% , which brings PO4 down with no side effects.

I would not make that same conclusion. A large water change may not actually drop phosphate that much due to the alrge amount potentialyl bound to rock and sand that can fairly quickly replace what was in the water if you cause a one time drop, but ongoing GFO can lower phosphate and keep it lower.

 

[Randy Holmes-Farley]

As for the PO4 leeching from rocks and substrate, I would say that the same goes for any export method, including GFO and water changes. Thoughts?

No, as I explained above.

 

[Pntbll687]

Hi fellow chemist enthusiasts,

for a long time I have been struggling with GFO, as every time I use it, SPS starts to lose tissue rapidly.

I wondering if there is any reasonable explanation from a chemistry point of view.

I have ruled out the hypothesis it is caused by rapid decrease in PO4. Every year I do a large water change of around 90% , which brings PO4 down with no side effects.

Some goes for the hypothesis of an alk swing, as I run a monitor and I did set it to test every hour, in the two days following the addition of GFO.

additionally, I do ICP every 4 months and there is never anything too high. Sometimes some elements are on the low, like boron, fluoride, potassium and strontium but the tank goes fine with that.

Any other ideas?


Also, I have tested several combinations of amount and flow in the reactor, and the tissue striping doesn’t happen if go slow. The problem is that is had to be too slow, enough to not make a dent on the phosphate.

I have been monitoring it and having the same bad results with a range between 0.1 to 0.6ppm, over the years. So, it is not that it is close to depletion either.

I’ve also tested 3 different brands of GFO with equal results. (Rowa, salifert, Aquaforest)

The alternative aluminum oxide doesn’t seem to have the same side effect, but slowly accumulates aluminumium which has been a problem in the past.

for context, it is a 500l tank packed to the brim with SPS.

Ok

Couple of questions
1. What is the phosphate level at?
2. How much GFO are you using?
3. What phosphate level are you shooting for?
4. Pics of the tank?

 

[arking_mark]

There is a theory around the relationship between Alk, PAR, N, and P.

Relationship between NO3, PO4, Alk, and PAR

There was a very interesting thread on this: https://www.reef2reef.com/threads/light-alkalinity-nutrients.319223/ My takeaway was: Post in thread 'Light, Alkalinity, Nutrients.' https://www.reef2reef.com/threads/light-alkalinity-nutrients.319223/post-9454985 If these are the general...

www.reef2reef.com

The key takeaways are:

• ULNS should have lower PAR and lower Alk.
• High N / Low P systems should have lower PAR and higher Alk.
• Low N / High P systems should have higher PAR and lower Alk.
• High N / High P systems should have higher PAR and Higher Alk.

If you are running a high P system, and things are fine and then transition to a lower P system, you may need to adjust other parameters to be successful.

However, I'm guessing it's more of a rapid change and availability of P causing the issue.

To reduce PO4, there are several things you can play with:

1. Feeding. Total amount and wet/dry ratio. Dry is much higher in P.
2. Export through more aggressive light cycle and pruning of macro algae in refugium or tank
3. Wetter skimming
4. GFO reactor
5. Linthicum Chloride or other P binding chemicals (I'm not a fan of this one)

Regardless of the method, changes must always be made slowly over weeks not days.