How quickly does GFO burn out?

specialk

Valuable Member
View Badges
Joined
Aug 13, 2013
Messages
1,001
Reaction score
296
Location
Cleveland / Lakewood, Ohio
Rating - 0%
0   0   0
So I have a phosphate problem on my tank. 125 gallons. (And my stupid hanna checker is lost as I can't seem to find it from my last move -- so in the process of ordering a new one so I can properly test)

I started running high capacity BRS GFO in a canister filter directly in the return of the sump. Followed the proper dosage and instructions for the amount I put in. Also doing 20% water changes every 2 weeks now like clock work for the last month. ( I was traveling a bit and did not do them consistently every 2 weeks like I had previously done)

I also added a very good amount of chaeto macro algae in the sump to help combat this (and because it should be in there anyways) as I did not previously have any in there

I ran it for about 3-4 weeks and, while I noticed a difference in my sps really starting to color back up, I am still however getting some bad algae developing in the tank.

Upon reading around on this forum, I am coming to realize that a tank with higher then normal phosphate can REALLY chew up the GFO and it needs replaced as often as every week -- sometime seven more?

I know the proper way is to test test test but just how fast does this GFO last when you are running it in a tank that has a higher then normal phosphate problem?
 
Once you figure out the number if it's super high you might have to change it every few days. Or once a week. Also to combat it. I talked to a few fellow reefers and even tho it's a expensive bottle on amazon it is made by ATM... Lanthium chloride. It uses the calcium in your tank to help export the excess phosphates out of your tank through your skimmer. It will knock your system to a true zero.
 
The time to depletion depend almost entirely on the phosphate level in the tank. So 0.1 ppm phosphate will deplete it 5 times faster than 0.02 ppm (very roughly).

At high levels, it likely depletes in less than a day.
 
It uses the calcium in your tank to help export the excess phosphates out of your tank through your skimmer. It will knock your system to a true zero.

The mechanism is lanthanum carbonate/phosphate precipitation. It does not involve calcium that I know of. :)
 
The mechanism is lanthanum carbonate/phosphate precipitation. It does not involve calcium that I know of. :)
Thanks guys!! So would you think that for someone who (and lets just say my assumption is right until I get the checker and get an accurate reading that it is at a high level) has a high level like mine, the best and safest thing to do is to just run GFO and make constant changes to the media and replace it, along with more frequent water changes ..? OR go with something that will work more quickly, like the stuff brownsalt92 mentioned?
 
Personally id use gfo and build a waterfall ats. That will keep the po4 low and more cost effective.
 
If you have it ratio'd correctly for tank size and tank load I found it can last a couple months.
 
Thanks guys!! So would you think that for someone who (and lets just say my assumption is right until I get the checker and get an accurate reading that it is at a high level) has a high level like mine, the best and safest thing to do is to just run GFO and make constant changes to the media and replace it, along with more frequent water changes ..? OR go with something that will work more quickly, like the stuff brownsalt92 mentioned?

I compare pros and cons of many methods, including GFO and lanthanum, here:

Phosphate In The Reef Aquarium
https://www.reef2reef.com/blog/?p=3184

from it:

Soluble Metals to Bind Phosphate

There are several approaches that add soluble metals to bind and precipitate phosphate. The most popular involves adding lanthanum, which precipitates as lanthanum phosphate and/or lanthanum carbonate (which itself may contain some lanthanum phosphate). The lanthanum approach is widely used in the pool industry to reduce phosphate, and seems to often work well in aquaria. It is also very inexpensive, using products such as Seaklear (make sure it is a pure lanthanum version as mixtures with other metals also exist). Note that this method reduces alkalinity, as removing carbonate and phosphate as a lanthanum precipitate will reduce alkalinity.

One way to use it is to drip is slowly just upstream of a particulate filter to catch and remove a substantial amount of the precipitate that is formed. One drawback to the lanthanum approach is that much of the precipitated material may escape capture and simply settle out in the system somewhere. That may not be an issue, but many aquarists do not prefer to accumulate such material. A second concern is that some people have observed problematic reactions from aquarium inhabitants. While there are not a lot of such stories, it is enough for many aquarists to look for other options.

However, due to its low cost, this approach is especially well suited to outside of the tank operations, such as the removal of excess phosphate from phosphate-contaminated calcium carbonate rock that is later to be added to a reef aquarium.

Soluble iron has also been used in this way, but not nearly so often as lanthanum.

Phosphate Export Using Binding Media: Granular Ferric Oxide/Hydroxide

In the past few years iron-based phosphate binding materials have become very popular among reef aquarists. These materials have been used commercially to treat drinking water (to remove arsenic, for example) and to treat wastewater (to remove a wide range of pollutants, including phosphate). They are sold to aquarists under a wide variety of different brand names, including PhosBan®, Phosphate Killer™, and ROWA®phos. These materials all range in color from reddish brown to nearly black. In a previous article I detailed how they function as well as some of the concerns that aquarists have had when using this material.

Even though the commercial materials appear to be reasonably large particles (Salifert claims 0.2 – 2 mm on its product label), they actually have a high internal surface area, somewhat similar to activated carbon. Consequently, apparent particle size is an unreliable means by which to gauge available surface area (though it is reliable for nonporous solids such as table salt). I have seen no measures of accessible surface area for the commercial granular ferric oxide (GFO) sold to aquarists. There are various modifications to the standard material, such as forming it into pellets (to perhaps work better in some applications such as media bags) and enclosing the GFO in a polymeric matrix (reducing the potential for breakage of the particles).

Phosphate bound to GFO surfaces is still available to the water column by exchange, so the sequestering is temporary rather than permanent. This fact is known in the literature3, and can be easily demonstrated by adsorbing phosphate onto GFO, and adding enough so that a detectable concentration of phosphate (0.1 to 1 ppm) is in equilibrium with the solids. Then remove the solid GFO and add it to seawater with no detectable phosphate. The now-detectable phosphate in the new seawater shows that the phosphate can be released from the GFO media when the aquarium’s phosphate concentration drops low enough.

One concern when using GFO is that it may add soluble iron to the system. This iron will likely benefit growing macroalgae, and I recommend adding soluble iron to systems that grow macroalgae. However, low bioavailability of iron may limit undesirable algae or cyanobacteria growth in some aquaria (and it can in parts of the ocean, as well), so adding iron might contribute to an algae or even cyanobacteria problem. In general, however, most aquarists find that the use of sufficient GFO causes a decline in algae, with the reduction in phosphate being more important to decreasing algae growth than the added iron is to promoting it.

A second concern with using GFO is that some aquarists find extensive precipitation of calcium carbonate near or on the GFO itself. It turns out that soluble iron can cause the precipitation of calcium carbonate. Such precipitation can turn bags of GFO into solid clumps, and may contribute to clogging pumps, but in general the effect, if noticed at all, is limited to objects very near the GFO. The extent of this effect may well depend on the degree to which calcium carbonate is supersaturated in the aquarium, as well as on the levels of magnesium and organics (both of which usually reduce the likelihood of calcium carbonate precipitation). Because of this potential for calcium carbonate precipitation, using this material in a reactor where it moves may be more important than for aluminum oxide media.

Finally, be sure to rinse these materials in fresh or saltwater before adding them to the aquarium, as fine particles may get loose in the aquarium, clouding and coloring the water, and possibly creating other problems. There is no efficiency drawback to this rinsing. Aquarists using the GFO in a fluidized bed reactor or canister filter can just run some fresh or salt water on it for a few minutes before putting it into the aquarium. A media bag of GFO can simply be rinsed with saltwater or RO/DI water a few times before adding it to the aquarium. Do not squeeze the GFO inside the bag when rinsing it, as that may break the particles into smaller bits that can escape the bag.
 
+1 on dropping phosphate too quickly. I'm experiencing unhappy LPS/softies and dying sps because I ran too much high capacity GFO too quickly.
 
Not to highjack this thread but how does one maintain a target level (0.03) with GFO once it has been reached?

Adjust the amount and/or replacement schedule to keep it where you want it. :)
 
Yea I got an angry toadstool looking like crap because I lowered nutrients to quickly. Go slow if you have a lot of corals.
 
I can tell by the frequent I have to clean the glass too
 
The instructions on my GFO seem to imply that their recommended dosage is based on the desire to remove, as opposed to prevent, phosphates. I'm basing this on the fact that the instructions say you should expect to see phosphates reduced to ZERO within 4 days. Therefore it seems safe to assume that once phosphates have been reduced to the desired level, further prevention should be achieved with significantly less GFO than the instructions say. The only way of knowing for certain is experience and frequent testing. Mine seems to get exhausted at around three weeks.
 
How about this ... running 2 little fishes phosban reactor and had GFO in there ... normal amount nothing crazy. Was running a Maxi Jet 900 pump and was working great. After about a week, it turned into a solid lump and the water would not even move it to where it was tumbling -- like it was doing for a good week and half. Once I removed the old GFO media and put new stuff in there, it started tumbling again and was good to go.

Is this an indication that it may have been exhausted?
 

IF YOU HAD TO TAKE A REEFING EXAM, WOULD YOU PASS?

  • Yes!

    Votes: 32 45.7%
  • Not yet, but I have one that I want to buy in mind!

    Votes: 9 12.9%
  • No.

    Votes: 26 37.1%
  • Other (please explain).

    Votes: 3 4.3%

New Posts

Back
Top