Hello everyone! I am currently building my sump and I was going to use passive carbon and filter media in the sump but I have changed my mind and decided I want to use a reactor instead. My set up is going to be a 40B with 700GPH glass-holes overflow into 20L sump and MAG 7 return pump. I am also implementing a refugium in the sump in the middle section. Now, for the volume of water I will have, roughly 50-53 gallons, should I employ the BRS GFO and Carbon in one reactor or use the BRS dual reactor and run the GFO and Carbon separately?
Reactor Recommendations
- Thread starter chuckawd
- Start date
Conesus_Kid
Premium Member
I would recommend running them separately. The schedule for changing them is different, plus they work best at different flow rates.
davidpesce
New member
+1 to separately. If you've got the space.
Gary Majchrzak
Team RC
look for two inexpensive/ used TLF reactors 
Sliceoftheocean
New member
+1 I agree with 2 TLF reactors they are easy to set up and get going.
AeonPhoenix
New member
Why's that? I just got some PURA Phoslock and the directions state that for first time use in a well established tank, to use x3 the regular dose to get started.
If you use a lot of gfo , you may reduce PO4 precipitously. A rapid drop to say less than .05ppm or so from high PO4 levels could stress some corals which may need time to adjust their phosphorous gathering methods. A rapid drop may also encourage more rapid precipitation of calcium carbonate and a consequent decline in alkalinity.
As for reactors:
Running gac and gfo separately enables individual flow control and changes.
I prefer the Two Little Fishes reactor. It's easier to change out ,imo and offers a good view of the inside so media can be observed. I have the BRS as well and it currently resides on the shelf.
In a reactor when a fine grained carbon like ROX 8 is used and extra piece of sponge at the top is useful to prevent carbon grains from flowing out.
As for reactors:
Running gac and gfo separately enables individual flow control and changes.
I prefer the Two Little Fishes reactor. It's easier to change out ,imo and offers a good view of the inside so media can be observed. I have the BRS as well and it currently resides on the shelf.
In a reactor when a fine grained carbon like ROX 8 is used and extra piece of sponge at the top is useful to prevent carbon grains from flowing out.
Gary Majchrzak
Team RC
I agree with Johnny and Tom- don't start using GFO "x3 the regular dose" to start out... start out slowly!
I don't even recommend starting out with the regular recommended dosage unless you're monitoring dKH closely.
AeonPhoenix
New member
Ah. So as not to shock your livestock. I see. I thought it was because you don't want the excess of gfo to immediately absorb all the phosphates and consequently leach them back in. If that were the case, I would cite that PURA Phoslock claims, "Will not leach phosphates back into the tank".
My gfo is in a 300 micron bag sprinkled throughout a healthy stuffing of polyester filter media in the hob filter. Fat chance it's tumbling at all, but the instructions claim that it's an option for usage.
I hear alot of debate about daisy chaining 2 reactors for gfo and gac - that it's not optimal because they have different life spans and flow requirements. Is this just a fussy and frugal thing common to the perfectionist nature of our hobby community? Or is it the case that both together will in fact work just fine, just not 100% - more like 80% instead..?
My gfo is in a 300 micron bag sprinkled throughout a healthy stuffing of polyester filter media in the hob filter. Fat chance it's tumbling at all, but the instructions claim that it's an option for usage.
I hear alot of debate about daisy chaining 2 reactors for gfo and gac - that it's not optimal because they have different life spans and flow requirements. Is this just a fussy and frugal thing common to the perfectionist nature of our hobby community? Or is it the case that both together will in fact work just fine, just not 100% - more like 80% instead..?
Any gfo should not leach back PO4 in normal conditions. The PO4 is bound to the oxide. Some might equilibrate if the water around it had a lower PO4 concentration than the gfo surface had already adsorbed. This would usually occur with a higher OH concentration in the surrounding water as is the case when regenerating gfo with sodium hydroxide.
Daisy chaining can work but gives less control over the media and flow through it in the individual reactors/ chambers. Different media will exhaust at different times and may be subject to different levels of clogging from precipitation and/or bacterial build up,etc. Personally, I use 2 separate rectors, running off one pump with a T plumbed in and individual ball valves on each individual reactor supply line.
The floss method sounds viable since it keeps the grains separate and should allow a good amount of surface exposure provide flow moves evenly and adequately through the floss.
Daisy chaining can work but gives less control over the media and flow through it in the individual reactors/ chambers. Different media will exhaust at different times and may be subject to different levels of clogging from precipitation and/or bacterial build up,etc. Personally, I use 2 separate rectors, running off one pump with a T plumbed in and individual ball valves on each individual reactor supply line.
The floss method sounds viable since it keeps the grains separate and should allow a good amount of surface exposure provide flow moves evenly and adequately through the floss.
thanks for all of the information everyone!! Very helpful you all always are and I am very thankful. I was thinking about using the BRS "dual" reactor where the GFO and Carbon are separate in their own reactors but then, like stated above, I would lose individual control of each reactor. Would you recommend I run 2 separate reactors and 2 separate pump? Also, is the consensus that the TLF reactor is better than the BRS single reactor?
davidpesce
New member
Never used the TLF, but the BRS works great for me.
Do you have the dual reactor running from one pump or 2 single reactors each with their own pumps?
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