Cyano and changing GFO

[Shilpan]

Just battling cyano here in my 400L, with live rock, 2 soft corals, and 4 fish (2 clowns, 1 bangaii, 1 fairy wrasse). Has a macroalgae refugium with 24/7 lighting, tank lights on for 7 hours a day. Tank is 2.5 months post cycle.

I finally got my new Salifert phosphate test kit from BRS. Now phosphate is reading 0. Nitrates are also 0-5ppm. I have a cyano bloom but it's not crazy, I would say the patches are covering maybe 5% of the tank or a little less.

My Seachem Phosnet GFO is 2 months old. The LFS says in his experience for understocked systems like mine it lasts 6-8 months, but he said use 4-6 months as a safeguard to change it. So how do you guys workout if GFO needs changing during a cyano bloom when phosphates are often 0? Cyano = needs changing?

Also do you have any suggestions for GFO brands or types of GFO? I do not use a reactor and want to buy whatever is cost effective. Or will I need a reactor at a some point?

 

[lmforbis]

I use the BRS GFO and I change it about every 6 weeks. I find reactors easy to use. I have a nice one from BRS but not sure if you can get that in New Zealand

 

[Shilpan]

We have a similar bulk GFO available. What's the cost per month for GFO? And how much did the reactor cost?

 

[2quills]

I've been using the high capacity GFO from BRS which is exactly what Phosnet from Seachem is and have no complaints. Running in the BRS deluxe reactor.

Change it every 6-8 weeks or so just for the sake of changing it.

I have a hard time believing it remains effective for too much longer than that. Eventually it's going to get clumpy and you will need to clean the reactor anyway.

Cost just depends. I figure I'll get about 2 years worth of GFO from the 1 gallon container I purchased. reactor and pump was a little less than $100 I think.

 

[Shilpan]

Ok thanks for that! I have a Nicely priced GFO here called continuum phos fe,

$23USD worth in a filter bag should last me 3-6 months, so I think that's reasonable. I'm trying to avoid reactors hahaha...

I think I'll take my GFO out and test my phosphate levels, if they rise then I can see if it's still working. Or maybe just test it in a cup of dirty water.