Carbon/GFO water quality

[jam.jo]

I am running 1/2 cup of granulated carbon and 5 tbsp of phosban GFO in a 2 little fishies phosban reactor on my 40 gallon. My tank has been running for 2 months. However.. my corals arent doing so great. I have a frogspawn that was extending and doing well for 24 hours but when I came home from work the next day it was sucked up into it's skeleton completely. I don't know if it is dead or not.. not sure what happened. But someone mentioned that it might be the gfo irritating the coral. Its been a week and it still hasn't recovered. I have 0 phosphates and nitrates but I did have a green algae covering parts of the glass which I cleaned off last night and the skimmer took care of it. Should I turn this reactor off and let some nutrients build up? I also have a refugium with chaeto on the back.

 

[Tisbe]

I have not had a problem with my corals and GFO. With that said, it will not hurt to take the GFO offline of a couple weeks and see if that helps. The nutrients will not go out of control in that time.

 

[JohnnyHildo]

i would be more concerned about water parameters with such a young tank. a sharp drop/raise in alkalinity will cause corals to react adversely.
also, if i read correctly you are running gfo and carbon in the same reactor which is not ideal. gfo works best when slightly tossed in the reactor whereas carbon requires even less flow to do its thing.
i have the same reactor and use it exclusively for gfo and for activated carbon just use a mesh bag which sits on top of the tray where my filter socks would hang.
once the algae was under control my replacement schedule kind of settled to around every 3 weeks where i switched out both gfo and carbon at the same time.

 

[lespaul339]

Honestly, it doesn't sound like the GFO is the problem to me. 5 tbsp isn't a whole lot. You have 0 nitrates and phosphates, but what are your water parameters testing at?

 

[Ebisan]

Running GFO and carbon in the same reactor is fine. You can keep them separate by having the carbon on the bottom with GFO on top separated by a sponge. The tumbling of the GFO prevents the GFO from sticking together. Or you can just mix the carbon with GFO and not worry about the need to tumble. GFO won't sitck to carbon.

 

[jam.jo]

I tested my parameters today:
Ammonia, nitrite, and nitrate are all 0
pH 8.2
Ca 450
dkH 8
Mg 1400
Phosphate .02 (hanna checker)
Temp 78
I honestly have no idea.. what happened... maybe something ate it? I have 2 peppermint shrimp, 1 coral banded shrimp, 1 emerald crab, a neon dottyback, hermits, a clownfish, diamond goby, and a pearly dartfish