How long for GFO to work on algae? A report.
 

I had a disaster in my 105---a feeder malfunctioned (well, yrs truly mis-set the aperture) and dumped a good cupful of quickly sodden and uncatchable spirulina into my reef. Which set off an epic algae bloom. After trying numerous things SHORT of GFO, I filled the double-size reactor (Two Little Fishies) with 2 jars of the stuff, on November 1 and let it run. (It's 1 jar per 50 gallons, and let it run about a month before changing medium)---Now, day 30, I have rocks clearing of the plague, strands of the stuff floating loose, and some of the far-side algae (from the current-blast of the Gyre) is now looking increasingly unhappy. I have lost some snails---they apparently don't like iron---but one is still tootling along munching film algae.

Once I started the GFO, (I'm in the middle of a kitchen remodel, so my tank has been sorely neglected, as in, I can't access it because of stuff from the kitchen,) I have not pulled any algae, just let the GFO work. And it is getting there. I'm going to look up the change-interval for GFO---under normal circumstances it's, I think, 3 months, but to get rid of this stuff---I may just go ahead and change it out to be sure. GFO doesn't give you any visual clue as to when it's absorbed all the phosphate it can take, and there was plenty in there. So I may just figure it's worth it to keep going.

When using lots of GFO, aren't you worried about it taking out too much too quickly?

What kind of GFO are you using? The only kind I can find (in my country) is by the pound bulk purchase, and I've no idea how much is needed to go in a reactor in one 'dose'.

I'm glad to hear it seems to be working well for you! I've been looking into getting some myself for my algae issues.

You can test the effectiveness by checking the PO4 of the water coming out of the reactor. If it is lower than the tank, it is still working, if the same, used up

Good notion, hkgar---doh! of course!

1 jar is 150 grams or a third of a pound. Treats 50 gallons. The brand I use is Phosban. There are several good brands of medium and of reactor. The reactors are not that expensive, and are good to have on hand if you have a problem again, or need to run carbon or something of that nature. There is also an adapter kit for bead-medium.

I've got a dual reactor, GFO/Carbon, I've just never used the GFO portion! Thank you for the conversion :D

This is the only way to know when to change it .

Fluconazole, its great you are doing it the right way and phosphates need to be eliminated regardless. But if your back is ever up against the wall. Do not be afraid of this treatment.

No negative aspects what so ever, and it works. I used 10 X 200mg caplets on 250 G total, and its all gone, bryopsis and GHA. Not working for brown hair algae, so I may try a higher dose.

Sure I suggested it but had never done it. Sunday I tested the water from the reactor - 15 PPB, than tested the tank - 5 PPB.

Interesting.

Good to know!

I just monitor my tank's phosphate level. If it starts to creep up, then I change my GFO. Mine will generally last about 3 - 4 weeks and I feed heavy and have a fair number of fish. A few years ago when I had a severe GHA outbreak (I wasn't home and things went south) I used Algae Fix Marine in combination of other things (manual removal, water changes, etc) and it cleared up in about 4 -5 months. It was a long battle but it can be won. Best of luck!!!

I have heard that GFO does not irreversibly bind PO4. If it gets saturated, it can slowly release PO4 back into the water column.

The algae will turn from dark green, to light green or pale brown and will be very easy to pull off the rock and stuff.
Once your parameters are back to normal....zero nitrate....zero phosphate.....zero ammonia....GFO is not helpful.......your biological filter should be doing its job...

Not sure what you mean by biological filter? The live rock and sand?

I am dosing carbon and using an ATS with a 90 sq inch screen and my PO4 creeps up and I periodically need to run GFO. Oh, and I have a skimmer, but that does nothing for po4

I find that my PO4 readings with ULR hanna checker ( if thats what your using) varies some test to test. I like the tool alot, but it has it limits. I consider both those readings pretty low. I quit running GFO when I got below 20 consistently.