How much GFO should I use??

[glennr1978]

I just bought some GFO from bulkreefsupply.com (pellets) and I'm wondering how much I should start with? I will be running it in a phosban reactor on my 40g breeder w/ 20g sump.

I read on here that too much GFO can be a bad thing. I definitely don't want to overdo it!!

[kaskiles]

1 tablespoon

[bertoni]

If there are any touch corals in the tank, I agree that starting out very small is a good idea.

[glennr1978]

<a href=showthread.php?s=&postid=13703936#post13703936 target=_blank>Originally posted</a> by bertoni
If there are any touch corals in the tank, I agree that starting out very small is a good idea.

It's pretty much all SPS.

[Todd March]

Uhmmm, what are your PO4 levels, that's really the starting point...?

[glennr1978]

<a href=showthread.php?s=&postid=13704379#post13704379 target=_blank>Originally posted</a> by Todd March
Uhmmm, what are your PO4 levels, that's really the starting point...?
Undetectable, but I'm only using an API test kit.

I've just noticed that I've had to clean the glass a little more than usual lately.

[glennr1978]

<a href=showthread.php?s=&postid=13704566#post13704566 target=_blank>Originally posted</a> by glennr1978
Undetectable, but I'm only using an API test kit.

I've just noticed that I've had to clean the glass a little more than usual lately.

It's kinda hard for me to believe that there isn't a PO4 issue because I have a large bioload considering the tank size, and I feed often. Although I rarely see any of the food go uneaten.

[Todd March]

The API phosphate kit is rough at best, so figure you're probably in the .02-.06 ppm area, which is good. Fruequency of cleaning the glass is an excellent indicator of what is truly going on in your tank.

Of course lower is better, but as you have read GFO's work marvelously. I think the suggestion of a tablespoon (or two) or so is an excellent place to start. Note that with already low levels of PO4 it takes the GFO a little longer to trap the phosphate IME—it's just a matter of the limited PO4 molecules being more spaced out in the water and the time needed for all of your system's water to pass repeatedly through the GFO enough to collect the phosphates.

When you have to clean the glass less often, you will know it's kicking in...

[bertoni]

I'd start with a small dose. 1 tbsp isn't a bad idea. The phosphate from the test kit might be correct, especially if there's a lot of macroalgal growth.

[glennr1978]

Thanks for the input guys!! One tablespoon it is.

Think I'll see better SPS coloring?

[bertoni]

Maybe...

[Lomholt]

Maby a newbie question, but what is GFO and how do you use it? People here at RC says that is works pretty well, but against what? Phosfat, nitrate or?

Maby we call it something else here in Denmark ;)

[Randy Holmes-Farley]

It is a phosphate binder, granular ferric oxide/hydroxide. Rowaphos is an example you'd likely have there. I discuss it here in detail:

Iron Oxide Hydroxide (GFO) Phosphate Binders
http://reefkeeping.com/issues/2004-11/rhf/index.htm

[Lomholt]

aaaah, yes I know Rowaphos. It is very used here ind Denmark :)

[Randy Holmes-Farley]

:thumbsup:

Happy reefing. :)

[bm102]

Quick question on this: I've read several posts (including this one) to start with 1 tbsp.

I am a bit confused. Assuming that one is using the TLF Phosban Reactor 150 the "Important Notes" at the top :) state that a min of 2 inches should be used as it is important not to over- or under-fill the column.

I'm guessing 1 tbsp barely gives you an 1/4 of an inch in the reactor... is it still ok to use just this small amount to start with?

[ccradr]

I was going to ask the same seeing that I run a Deltec reactor with half a liter of Rowaphos per the instructions on the container....ofcourse I have 265 gallons

[bm102]

ccradr yeah I'm curious!

Before I sound completely ignorant of reading instructions please let me add one note: I know that it says you can fill the remaining space with say GAC. However if I understand correctly the GAC would deplete faster than the GFO and it would be a mess trying to just change out GAC.

So assuming one only wants to run GFO in something like the TLF 150 is it ok to just start with 1 tbsp in the reactor?

[JAG107]

IMO that API phos test is junk, my water tested at undetectable with API and 0.5 with salifert. The condition of my corals were more consistent with the salifert result, so I added a bag (maybe 150 or 200g) of GFO to a high flow area in the sump. Along with a new skimmer, after 5 weeks its down to less than 0.1. So I used more than 1TBSP but alas it isn't in a reactor, so I don't know how differently that affects it.

[bertoni]

1 tbsp will be fine. GAC does seem to be depleted more rapidly, in the average system, anyway.

[GeoffM1968]

Funny as I found this thread after I set up my Phosban Reactor 150 after reading about it in a couple other threads. I put 150 g of PhosBan in it. Rinsed it thoroughly but made mistake and did not read all the instructions and let it tumble. Could not figure out why tank clouded until later when I went back and read the bottle.

Reading this thread and instructions on the PhosBan, the amounts recommended differ widely.

[bertoni]

[welcome]

My guesses tend to be very conservative, since people have reported issues with using large amounts of media on tanks with Acropora and similar stony corals.

[GeoffM1968]

Yes, thank you. Based on your experience and information, I turned mine down to a trickle and watching parameters closely.

At times we are all scientist conducting our little experiments and use past knowledge to build our own. Only when we ignore past knowledge do we deserve what we get.

[pkpthrillho]

I bought a 1 pound pack from BRS also and put maybe a handful in a media bag. Phosphates went from .5 mg/l to < .03 mg/l


I scrubbed all the hair algae and brown algae off the glass and did a water change, we'll see how it does to keep the HA down or kill it off entirely. My clowns do seem more lively...

[Lomholt]

<a href=showthread.php?s=&postid=13713646#post13713646 target=_blank>Originally posted</a> by GeoffM1968
Funny as I found this thread after I set up my Phosban Reactor 150 after reading about it in a couple other threads. I put 150 g of PhosBan in it. Rinsed it thoroughly but made mistake and did not read all the instructions and let it tumble. Could not figure out why tank clouded until later when I went back and read the bottle.

Reading this thread and instructions on the PhosBan, the amounts recommended differ widely.

Maby a silly question, but did you "compress" the phosban to stop the tumble?

How do you know when to change the phosban in your reactor?

What waterflow should be pumped through your reactor (how big is the reactor?) ?

[GeoffM1968]

I did not compress it as you want the up flow reactor to permeate the substrate. It is suppose to be good for 3 months but you should depend on measuring phosphates and replace when it goes up (all environment variables constant).

Specs say, "Requires a flow rate of approximately 80 gallons per hour." It is 4 IN. X 4 1/2 IN. X 17 1/2 IN.