Two Types of GFO:
- Granular GFO is varied in its shapes and requires the least amount of flow to tumble. Good for reactors.
- High Capacity GFO is twice as dense as Granular GFO, so twice as much material will fit into a reactor. It's extremely hard and has less dust to begin with. Fewer fines will be created during use and transportation. By volume, High Capacity GFO will remove roughly twice the phosphate compared to the same volume of Granular GFO. Best overall performance.
Special note on fighting existing algae problems: Algae needs three main nutrients to grow: phosphate, nitrate and light. Reducing any one of these will significantly slow down algae growth but may not completely solve your issue. Once algae takes hold, it can be a difficult battle but it is winnable. The best offense against algae is to take preventative measures and attack nutrient before an outbreak is apparent. Use the following suggestions and be aggressive if an algae problem is already present:
- Maintain undetectable phosphate levels with good feeding habits and use a phosphate remover like GFO. 99% of all phosphate is added to the tank via foods.
- Control nitrate levels by reducing feedings, increasing the water change schedule and maintaining a properly sized protein skimmer.
- Use nutrient free RO/DI water for water changes and top off water
- Shorten your lighting period or intensity. In some cases aquarists have found replacing old bulbs that have fallen out of their intended spectrum helps as well.
- Continuously remove as much algae as possible by hand.
- Add predators - nothing helps an algae outbreak as much as critters who eat it all day long. Various tangs, lawn mower blennies, crabs and snails are all good options. It is also theorized that a healthy pod population will also control algae growth before it gets a chance to take root.
Note: All Bulk GFO is packaged by volume.
High capacity GFO By William on 11/17/2017William would recommend this product to a friendUSE WITH CAUTION! This product works and works very well. Unfortunately it worked a little to well for me and stripped enough nutrients out of my tank that my sps corals started to bleach. By the time I figured out what was going on it was to late for the majority of them. I used the recommended amount for my tank based on the BRSF calculator. After a lot of research I found many other stories like mine. If you use this product in reef tank you should introduce it slowly. Gave this product 4 stars mostly because there is no warning on the potential problem it can pose to a reef tank. The product itself is 5 star and works very well.
HC GFO worked great By Carmen on 10/31/2017Carmen would recommend this product to a friendI had a phosphate reading of 5. Two days after starting the reactor it read .2 and the day after that barely 0. It may be zero now but it's been a few days since I've checked. Happy with the results. It was faster than I thought it would be.
Nice product By Kirti on 8/2/2017Kirti would recommend this product to a friendThis works pretty well and rinses clean very easily. Definitely ordering again.
I do not like it By Dunghan99 on 7/20/2017Dunghan99 wouldn't recommend this product to a friendI was using phosguard for a month a all my corals was doing fine, so I decided to try out gfo since they have very high review,only use half the recommend doses and after a week all my zoas react weird and some of them melted.
Effective and Efficient By Chivo on 6/13/2017Chivo would recommend this product to a friendI use this GFO on a BRS reactor with Carbon and it reduced my Phosphates to 0. When I get any reading (0.01 or more on my Hanna), I change the media an it immediately goes back to 0. Excellent product.
Excellent product By Carlos Vicente on 5/23/2017Carlos Vicente would recommend this product to a friendI have tried different brands of GFOs and BRS High Capacity GFO is the best of all. Worth every penny, don't waste your money on fancy name brands.
Worth every penny By Will on 3/21/2017Will would recommend this product to a friendI upgraded to this High Capacity GFO from the normal BRS GFO about 6 months ago. I get roughly twice the life out of this stuff which is important because I am lazy at switching my media and I travel for work a lot. So any time I can save working on the tank to enjoy it more is worth it in my book.
Low residues or particulates By Anibal on 12/16/2016Anibal would recommend this product to a friendVery high capacity last longer than regular brand with almost no residues.
Performs great at a great value By Allen on 11/24/2016Allen would recommend this product to a friendVery little dust, lasts much longer than other GFO and at a solid return for your money.
Worth the money By Adam on 6/26/2016Adam would recommend this product to a friendQuick to rinse, works great.
dan would recommend this product to a friend By dan on 6/14/2016dan would recommend this product to a friendVery good product.
BRS Bulk GFO Granular Ferric Oxide - High Capacity By Ernie on 2/6/2016Ernie would recommend this product to a friendVery good product
Ask a question
It will not release back phosphates under aquarium conditions.
It depends on how large your tank is. The easiest way to do the math is to use our reef calculator at the link below. You enter the size of the tank and the type of GFO you want to use, it will tell you how much GFO to add.
For a tank that size you would want to run 1 cup of GFO. The easiest way to do the math is to use the BRS Calculator right here:
The GFO HC is a denser/harder product which means it can handle more flow without breaking down (though at the same flow, its tumbling characteristics would be about the same). If you are trying to increase flow you could also remove the sponge pads in the reactor when using GFO.
It sure will. Its a great combo if you need something that is hang on back!
Thanks for getting in touch with us in regards to having too low of phosphate to allow for healthy corals. If you are using this and are not supplementing in amino acids/ target feeding, there is a change of corals bleaching and dying off slowly due to low availability of nutrients that they need. Please let me know if there is anything else that we can assist with. Thanks!
That's a great question! What we have found to work well for us is to cut the amount of gfo down based upon your change frequency. For example, if you change your carbon every two weeks, and would normally change your gfo every 4 weeks, just use half as much gfo as the calculator recommends and this will bring the gfo capacity more in line with your carbon schedule and avoid wasting extra media.
It is a good idea to rinse GFO quickly with tank water to wash off any small dust. Feel free to let us know if you have any further questions!
GFO will help to remove silicates from the water slightly. It sole purpose however is for phosphate removal.
Overall you will use our aquarium calculator to find the correct amount between 2.5 cups for regular GFO and 1.25 cups for High Capacity. With this said you can use a single reactor for High Capacity and a larger reactor would be needed for the regular GFO. Feel free to let us know if you have any further questions!
There will be 8 cups in a half gallon container.
It is best when tumbled in a fluidized bed reactor as the media otherwise has a tendency to harden into a brick, but even placed in a filter sock would be better then nothing.
There isn't any minimum size limit to the high capacity gfo. It can be used in any aquarium it just happens to be more popular in larger tanks because you don't need as much media. Its handy when your trying to keep the equipment smaller while still maintaining the same effect.