New to GFO

Sawdonkey said:
The water is not supposed to come out reading Zero after the first pass. It's a continuous process. Just let it run, and your overall PO4 level will gone down. Quit wasting your time testing the water of the reactor output and just let it run. Test your tank water in about a week.

It has nothing to do with your test kit and you're wasting GFO if your throwing it out after one day. It just isn't 100% efficient.
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This is/was the answer I'm looking for Thanks...
 
Testing the output will show if the GFO is exhausted. Do not expect a 0.00 tank by running GFO. It is one way to lower P04. Make sure the GFO or carbon is not getting too much flow. If they grind together too much, it will cause a dust to be all over the system. I run 1/2 cup on a 120. That stuff works well, my system would get shocked if i used too much. Again keep the flow rate so just a top layer floats, that is maximum flow to me.
 
SloppyWhenWet said:
Testing the output will show if the GFO is exhausted.
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I disagree. I'm speculating here, but the GFO is not 100% efficient. It doesn't make 100% contact with 100% of the water. Even with brand new GFO, some PO4 will slip through the reactor. It's not a filter that is straining PO4, it's just a media that binds PO4 if it makes contact with the GFO, and it doesn't make 100% contact.

I still think it is a waste of time to test your reactor output. This is probably better answered by Randy Holmes Farley over at R2R, a real chemist, but I think he'd answer the same way?
 
Sawdonkey said:
I disagree. I'm speculating here, but the GFO is not 100% efficient. It doesn't make 100% contact with 100% of the water. Even with brand new GFO, some PO4 will slip through the reactor. It's not a filter that is straining PO4, it's just a media that binds PO4 if it makes contact with the GFO, and it doesn't make 100% contact.

I still think it is a waste of time to test your reactor output. This is probably better answered by Randy Holmes Farley over at R2R, a real chemist, but I think he'd answer the same way?
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Yeah I doubt it filters everything but if you wanted to see how long the gfo lasted.
Tank test at 0.20ppm
Effluent test at 0.5ppm day one
Tank tested at 0.18
Effluent test at 0.17 day 30
The flow rate should be really slow so maximum binding occurs. I don't like to grind my media so I run it as slow as possible.
It can be hard to reach zero and trying to do it in a few days or a week is crazy.
As my Fuge grows my levels drop to 0.05 then as the Fuge gets full it doesn't work as well til I cut back and let it grow again. I am sure many other have methods for keeping everything in check but I haven't figure it out yet. Blind luck for me.


Drinking from a fire hose and reef keepin have all too much in common!
 
SloppyWhenWet said:
Yeah I doubt it filters everything but if you wanted to see how long the gfo lasted.
Tank test at 0.20ppm
Effluent test at 0.5ppm day one
Tank tested at 0.18
Effluent test at 0.17 day 30
The flow rate should be really slow so maximum binding occurs. I don't like to grind my media so I run it as slow as possible.
It can be hard to reach zero and trying to do it in a few days or a week is crazy.
As my Fuge grows my levels drop to 0.05 then as the Fuge gets full it doesn't work as well til I cut back and let it grow again. I am sure many other have methods for keeping everything in check but I haven't figure it out yet. Blind luck for me.


Drinking from a fire hose and reef keepin have all too much in common!
Click to expand...

I guess that would give you an idea, but you have two variables to deal with. That's not even including the amount of PO4 you're putting in the tank with feeding. I'd rather just keep it simple and just test my tank water because that's all that really matters in the end. When I see PO4 going up, I replace my GFO. By the way, my GFO lasts multiple months (3-4), but that could be because I'm also exporting some PO4 with my biopellets.
 
SloppyWhenWet said:
Yeah I doubt it filters everything but if you wanted to see how long the gfo lasted.
Tank test at 0.20ppm
Effluent test at 0.5ppm day one
Tank tested at 0.18
Effluent test at 0.17 day 30
The flow rate should be really slow so maximum binding occurs. I don't like to grind my media so I run it as slow as possible.
It can be hard to reach zero and trying to do it in a few days or a week is crazy.
As my Fuge grows my levels drop to 0.05 then as the Fuge gets full it doesn't work as well til I cut back and let it grow again. I am sure many other have methods for keeping everything in check but I haven't figure it out yet. Blind luck for me.


Drinking from a fire hose and reef keepin have all too much in common!
Click to expand...

Great information here... Firehose -- yes...

Stopped testing until I get the Hanna, I think API is difficult to read or at least see a clear difference between .025 and 0.05. I just thought new GFO would test zero since I put so much in. Fortunately I don't have any corals to shock yet, and all other parameters are staying good, well 0, only number above zero is Phosphate. I think I have a lot of water and very little bio load, so Nitrates will rise but it may take another month or so.
 
Sawdonkey said:
I guess that would give you an idea, but you have two variables to deal with. That's not even including the amount of PO4 you're putting in the tank with feeding. I'd rather just keep it simple and just test my tank water because that's all that really matters in the end. When I see PO4 going up, I replace my GFO. By the way, my GFO lasts multiple months (3-4), but that could be because I'm also exporting some PO4 with my biopellets.
Click to expand...


Agreed... keeping it simple for now, didn't expect so many responses on GFO reactor output, I just thought others tested direct output and I was doing something wrong, but, sounds like the reactor is going to spit PO4 out no matter how new.
 
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Ok Guys,

Thanks for the advise. Figured I'd post an update after getting the Hanna checker (Low) and running the tank for a month or so. The results are interesting. I have changed the full GFO reactor 2x over the month, in an attempt to get down to the "recommended" parameters of .03ppm PO4 ( http://reefkeeping.com/issues/2004-05/rhf/ ). With a rich Refugium even growing coralline algae and GFO overdose, not happening. So I did more study and found that some salt mixes actually test for phosphates. On accident I'm using Oceanic, which turns out to have some of the lowest RODI mix PO4 levels. So, I tested a fresh mix of RODI and Oceanic mix and got 0.00ppm PO4, which would be the lower of the two test samples in the screen shot .02 and .00 or the Hanna checker can't distinguish .01 or .02 ?? Not sure what else could be done to bring PO4 down, APEX does a nice job of organizing my Hanna tests, and as you can see PO4 is not rising, its just bouncing up and down in fractions of a PPM.

So... the magic question is the output from the BRS GFO lower in PO4 than the tank, yes, it typically measures .04 less than the tank right after a media change and .02 after 3 days.

Based on my research, I'm going to go back to manufacturer recommend GFO for a 150 (2 tbsp / 8 gallons) or just over a cup, working up to 2 cups, changing every 4-8 weeks. It seems 1 cup or 3 changes reactor output by .04 compared to the tank, within a day or so then drops to .02.

I'm sure the API tests are less than the best quality, but, interestingly they match (as close as my eye can see) the Hanna results. So... not sure how to get to .03ppm or even if I need to get to .03. Currently bouncing from .05 to .17 and everything in the tank seems happy.

My conclusion is that unless the PO4 is over .25, I'm not going to worry at all. To me it appears that the test equipment, test kits, salt mixes, etc could introduce .10 into the equation and it doesn't seem like it's going to impact growth or water quality.

The above said, if anyone has better information, better test kits, or feels there is something better that I should be doing with PO4, I'm interested.

Thanks again for all of your help and input.

JW
 
Hey Jay,

They have two pieces to the "accuracy" ±0.04 ppm ±4% of reading. So... could be .04ppm which would be huge in the scope of 0-2.5ppm with a .01 resolution. If it's 4% of the reading then .03 "suggested reef value" would only be .0012ppm. Even at my highest level of .35 that would be .014 so... .336 to .364 would be no big deal. Anyhow, if the meter is .04 and considered the best "affordable" home PO4 tool, how do you know if you are at .03? Do you think measuring below .25 is necessary or a waste of time?

Thanks,
JW
 
1jwampler said:
The above said, if anyone has better information, better test kits, or feels there is something better that I should be doing with PO4, I'm interested.
Thanks again for all of your help and input.
JW
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I came to the same conclusions, but kept looking for better test equip. The Hannas are not as accurate (repeatable) as advertised unless used very precisely. Their reagents from batch to batch had far too much variance. I'm now way over the top http://www.chicagoreefs.com/forums/showthread.php/18251 but previously I was using the milwaukee MI412 http://www.milwaukeeinst.com/site/products/products-by-parameters/phosphate. It was more consistant than the hanna. From reagent lot to lot the milwaukee didn't have the same variance. It was also easier to get 100% the reagent out of the packets and was much more repeatable when testing sub .10 water.
 
1jwampler said:
Anyhow, if the meter is .04 and considered the best "affordable" home PO4 tool, how do you know if you are at .03? Do you think measuring below .25 is necessary or a waste of time?
Thanks,
JW
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Correct, below .10 the hannas aren't be best option. I find measuring below .10 to be necessary for my reef, it po4 creeps up into the .12 range I've had sps problems. I keep mine between .02 and .09 before changing gfo.
 
Thanks Jay,

Just looked at the Milwaukee specs seem the same as the checker, but, looks like the Hanna higher end units. Probably overkill for my mixed reef tank. Until I did research, I got lots of info from different LFS, etc that just wasn't right. The one LFS guy I trust said use Oceanic salt, I did because he said, so, not because I knew why. Now that I have done the research, it appears that either Red Sea or Instant Ocean are the best to keep PO4 out of the water from the start. What salt mix do you use?
 
1jwampler said:
Just looked at the Milwaukee specs seem the same as the checker, but, looks like the Hanna higher end units. Probably overkill for my mixed reef tank. Until I did research, I got lots of info from different LFS, etc that just wasn't right. The one LFS guy I trust said use Oceanic salt, I did because he said, so, not because I knew why. Now that I have done the research, it appears that either Red Sea or Instant Ocean are the best to keep PO4 out of the water from the start. What salt mix do you use?
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When I first purchased the Hach unit, I ran it against the hanna and milwaukee. The specs may list them similar, even with good lab pratices, the hanna was never accurate (repeatable) below .10.

I use good ole reef crystals. Simple, cheap, and a lot of great sps tanks have success with it.
 
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