View Full Version : GFO Flow through reactor?

09/17/2017, 07:32 PM
I have a BRS Mini Reactor on my 29gal tank to reduce phosphates. I run a mix of GFO and Carbon in it. I think i ran a big too much GFO at first because some of my SPS has turned white in spots. Im assuming it removed the phosphate at to quick of a rate and shocked them. I cut the amount of GFO in half, but my question is should i reduce the flow as well? Does the flow of water through the reactor remove phosphates faster if it is higher?

Keep in mind that this is the mini reactor so the GFO does not tumble so i can turn the flow up all the way if i want.

09/17/2017, 10:31 PM
I suspect that running with lower flow will reduce the rate of adsorption, but that's dependent on a number of factors, such as the residence time for the water and criteria for adsorption onto the GFO. Cutting back on the amount in the reactor might be easier, and could have a very similar effect.

09/18/2017, 06:50 AM
Just a note, once the bed in a flow reactor becomes small, the rate of removal becomes nonlinear because of channeling making the reactor less effective than you expect. So, alternatively, keep the reactor filled as it is now and try this.

You can get an idea of how often the water is treated (turnover time) by your little reactor by measuring the flow rate through the reactor in gallons per hour then divide the number of gallons in your system by the flow rate and multiply this quantity by 9.2. This will tell you how many hours are required to treat 99.9% of the water. A longer turnover time means a slower phosphate removal rate.

Slow the flow down, measure that new rate and figure your new turnover time. There is no way to know what the correct turnover tme is, but shoot for 1/2 or 1/4, and see how the system and phosphate level respond.

09/18/2017, 07:10 AM
. I think i ran a big too much GFO at first because some of my SPS has turned white in spots.

What is your current phosphate level?
What has the phosphate level been trending at?

I recommend using GFO when you have a phosphate issue.. I do NOT recommend running it continuously as its rate of removal is not easily tailored and it can do more harm then good if you run it when you don't really have a phosphate problem..
Many newbies think you need to have a GFO reactor to have a successful system.. And that would be wrong..

09/19/2017, 06:07 PM
i reduced the amount of GFO to 1/4 cup and cut the flow down. That was a few days ago. I just tested my Phosphate and it is .02

09/19/2017, 06:26 PM
That level should be safe, if the kit is accurate. I'd wait to see how the tank responds.

09/21/2017, 12:02 AM
As far as removing phosphates faster ? I'm not sure but the way I've ran gfo for my self & others for the past 10 years
The granular gfo should be tumbling in the reactor
The brs mini is like a 5inch canister I think I wouldn't put in more then 1 inch for limited time since you have acros
I'd get a second reactor for the carbon and fill it as to the brim packed as tight as you can sorta opposite what you do with gfo