how much gfo?

[CoralBeauties]

How much gfo do you think that you can use without any problems?  I did a water change this past saturday night.  I also replace my gfo that was one cup worth and a month old.  I added 2 cups of fresh rinsed gfo.  The next day my toadstood leather was shrunk up.  My toadstool is always a good way to tell that something is not right or has changed.  I noticed tonight a frag of grape sherbert acro has some tissue shedding off at the very edge of the encrustation on the rock.  I shut down the reactor.  Hope this will stop the shedding.
Jeff

[Logzor]

Jeff,

Are you running GFO to tackle an algae issue or for just general maintenance to keep phosphates down?

I have not had issues running the recommended amount that is usually listed on the product. Usually the only problems with GFO is that it will take too many phosphates from the water! Corals need a certain amount of nitrates and phosphates. I sucked so much out of my tank at one point my acropora began to lose a bit of color. Increased feedings fixed that pretty quickly, though.

I doubt that peeling skin and the shrunk of leather are directly related to the GFO. It is most likely something else. Leathers in my experience are very fickle and will close up for no reason. The peeling acro is a sure sign of a problem on the other hand.

Slow tissue necrosis is most often due to low alkalinity, less that 7.5 DKH, or a swing of a few points in a short amount of time. It can also be caused by stress from elevated nitrate and phosphate levels.

What is the current status of your tank as far as algae and nutrient issues?

I would hold off on the GFO and do water changes every other day of around 10-15%.

[verper]

GFO usually only causes problems if you have excess phosphates and they are absorbed too fast with the GFO.  The quick drop is what causes problems.  Do you have any idea what your phosphates were before the change?

[CoralBeauties]

My test kit always shows 0 phos and 0 nitrates.  I usually judge when to change out the gfo when I start to see some algae growth starting back up.  I did have several patches of red slime algae and it had been a month since my last gfo change.  I wanted to double it up but maybe it was too much all at once.  All of my water parameters test out good.  Alk is in the range of 8.6-9.  It is either the gfo or I hope it isnt an issue with red sea coral pro.  I wouldnt think that the salt is the issue since I am almost to the bottem of the current bucket that I am using and I havent seen any issues with it yet.
  If this recession keeps up what should I do with this coral?  I would guess I should cut off any of the coral above the receding area to hopefull save at least that part of it.
Thanks
Jeff

[verper]

It shouldn't be the GFO if phosphates were at 0 but by what you are describing, it could be.  There are several accounts on RC where rapid phosphate loss caused RTN.

The Red Sea thing is more of a general decline in the health of the tank even with water changes.  Not a fast decline.

Yes, if the recession continues, frag it.

[lazylivin]

I was going to guess that is was GFO. GFO can suck the alkalinity out of the water very rapidly. But sense you said your alk is normal range guessing it is not that but may want to double check your levels just to be sure.
I have to compensate for it when I change it out but then I have very small water volume.

[yinyang]

jeff
u might want to check your ph
lots gfo will reduce your ph
might cost some problem for your coral

[verper]

Good call Bin.  I've read that can be another problem.

[CoralBeauties]

Well I got home today and the coral has stopped shedding.  Looks as if it only lost about an area about 1/8 inch wide by 1 inch long, not bad at all considering.  The toadstool is still shrunk up but they are always slow coming out of it. 
  I did check the ph last night and I was at 8.14 but it might have dropped overnight the evening I changed out the gfo.
  This hobby has a constant learning curve to it.  Unfortunatly sometimes our corals are the ones that suffer.
Jeff

[verper]

  This hobby has a constant learning curve to it.  Unfortunatly sometimes our corals are the ones that suffer

Agreed.