How often to replace carbon/gfo when...

[Chicagoreef2016]

My phosphate levels have always shown 0 on my salifert tests. But I know that isn't the case as I have had GHA in past, and now some cyano hanging around with phospahate at 0.

Parameters have been stable at the following for over 8 months:

ALK: 8.3
Calc: 415
SAL: 1.026
Nitrate: less than 1
Never check pH

So, how often should I change out the contents in my dual reactor (BRS with carbon/gfo mixed together)? Any visual clues I should watch for? 2 weeks? 3 week? Dare I say 4? I have noticed that the stuff on the glass has slowed down tremendously the more I change it out.

Thanks.

 

[mcgyvr]

First.. GFO and carbon typically have different exhaustion rates and GFO is typically expired (used up) long before carbon..
GFO's exhaustion rate is dependent on the amount of phosphate in the system and one would typically monitor the output of their reactor and change it when the output isn't zero..
I think as a general rule GFO = 2weeks or less
carbon = 1 month..

and I'm not sure why people think cyano is directly attributed to phosphate.. my experience shows its not at all..

Personally I've never ran GFO and never intend to..
and while I haven't been running carbon in a long time I plan to have a small reactor on my new tank just because I will have more money invested in corals than ever before and run a mixed reef with softies that "can" release toxins so I'm planning on the carbon just as an "in case".. and its cheap..

 

[Sk8r]

Cyano is not algae. The full name is cyanobacteria. Animal kingdom---sort of. It thrives on old lightbulbs, weird sunlight, and just occasionally because it's got a foothold.

Just FYI, GFO can saturate pretty quickly, as in, in a week in a tank with a lot; this is why I recommend a monthly change until you see improvement.

 

[billdogg]

I would suggest running your GFO and carbon separately as well. I change mine when I do water changes (in my case, every 4-6 weeks). I use just a small amount of GFO in a TLF 150 reactor for my 120DT on a as-needed basis, and a BRS single reactor for carbon that I run 24/7/365 and have for almost 30 years.

 

[Snaredrum]

GFO and carbon change outs monthly or every other water change for me.

 

[Chicagoreef2016]

Thx for the info. I think I will separate out my carbon and GFO; my phosphate has always tested at 0, with and without GFO, so testing for me is not much use at this point. I will keep trying, but have to rely on visual clues in my tank. I only have 5 fish and don't feed much frozen (1-2 times a week), so my overall bioload shouldn't be that high. So, I will look to swap out carbon every 3-4 weeks, GFO every 2-3 tops. And see where that goes. I have some new SPS given to my by a friend (expensive sticks) that I am trying to bring back from a not healthy place, so if I change out my carbon/gfo a little sooner before they "wear out", at least I will be keeping my tank consistent from a parameter standpoint and not having any slight increases in phosphate.

 

[Jon0807]

Phosphates are probably reading 0 cause the GHA is absorbing it. As for the cyano, I recently got hit fairly hard with it. Chemiclean worked wonders. And it's reef safe!