Reactor

[Tanked79]

Is there honestly a reason for a reactor if i have a fuge and sump on my tank???

[blanden.adam]

The short answer is yes, but the details depend on exactly which reactor you are talking about? Carbon, GFO, biopellet, calcium, kalkwasser, sulfur, or other?

[avelino78]

How about carbon and GFO??

[blanden.adam]

Sure, there are a couple of reasons to run both.

Carbon: These are good at removing dissolved organic compounds (DOC) -- be they from coral alleopathy (especially from soft corals like leathers), or from exogenous sources, it will help remove them. Also, before GAC, saltwater tank water turned yellow after a while (i'm not sure the compound responsible or how long it took, this is just something I've heard from multiple people who used to keep saltwater tanks before it was widely used), so GAC will also help keep your water nice and clear.

GFO: GFO is a good binding resin for phosphates and similar compounds (e.g. silicates). The GFO will help keep your phosphates nice and low and prevent nuisance algae growth.

The presence of a sump is irrelevant to either of these (except it makes them easier to hide). A refugium will help reduce nutrients if you are growing things like macroalgae in it, but it actually is a relatively poor exporter of phosphate. GFO is really your best bet for phosphate control (in addition to proper husbandry and a quality skimmer).

[chrisfont23]

Originally Posted by Tanked79

Is there honestly a reason for a reactor if i have a fuge and sump on my tank???

I run both a Nitrate reactor and a Phosban reactor with a fuge/chaeto.

[Palting]

There is no reason to have a GFO reactor if your phosphates are low or undetectable. Carbon does not need a reactor. Mesh bag will do just fine. I use a refugium, have undetectable phosphates and nitrates, have not had a need for GFO reactor in 3 years since the reef started.

[blanden.adam]

Originally Posted by Palting

Carbon does not need a reactor. Mesh bag will do just fine.

While you can run carbon in a mesh bag (and I have done so in the past, especially quarantine systems where you want to keep cost low), it really is much more effective if run in a reactor. You just ensure that the water sees all of the carbon, and that the carbon sees a lot more water.

[Palting]

Not so sure I agree with you. It all depends on where you put the mesh bag, and where you put the reactor. Let me illustrate.

Lets say the sump flow is 900 gph. That's my sump flow.

I use a reactor, with a pump that is, say, 132 gph. Thats the pump that comes with the NextReef MR1 reactor complete, rated good for up to 250 gallons. I used to use it for GFO, now it just sits on a shelf storage. It will process 132 gph of tank water.

Instead, I use a mesh bag. In my reef system, the mesh bag with 2 cups of GAC thinly spread sits in a tray where ALL the sump flow MUST go through. In my predator tank system, the mesh bag lays between two baffles, thinly spread but occupying that whole space, so All the flow MUST also go through carbon.

So, the mesh bag processes 900 gph while the more expensive NextReef MR1 only processes 132 gph.

I can replace the MR1 pump with a 900 gph pump. However, given the smaller volume within the reactor compared to the sump volume, the carbon will get pulverized. It all depends on how you set it up, but a mesh bag CAN be 9X more effective than a reactor.

[coralsnaked]

The use of activated carbon in salt water works through absorption and it is gelbstoff compounds that it removes preventing water in an aquarium from getting the yellow tint. It also removes large organic molecules like: medications, chlorine, pollutants and toxins, as well as many other types of chemical elements and compounds from the water that a protein skimmer or another means of filtration may not remove.
Activated carbon will also remove the trace elements and minerals that are important to your fish and often leaches phosphate into the aquarium. Therefore running GFO in addition to carbon usually is a no brainer and additional supplementation of trace as well as major foundation elements can be needed. Small systems can utilize a single reactor to run both at same time. My suggestion is to run carbon only when there is really a reason and depend more on adequate protein skimming.
In order for the carbon to be most effective, water must flow over/through the carbon material and this is best accomplished thru a reactor but will work less effectively in a mesh bag in high flow areas. And use only the amount needed, don’t overdo it. Normally about 3 level tablespoons of carbon per 50 gallons of volume should be sufficient to keep water clear. It is best to use smaller amounts changed more often. And remember the addition of carbon and significantly clearer water can expose corals to too much UV light to abruptly and can lead to coral bleaching, and possible death.

Merry Skerry

[blanden.adam]

Originally Posted by Palting

Not so sure I agree with you. It all depends on where you put the mesh bag, and where you put the reactor. Let me illustrate.

Lets say the sump flow is 900 gph. That's my sump flow.

I use a reactor, with a pump that is, say, 132 gph. Thats the pump that comes with the NextReef MR1 reactor complete, rated good for up to 250 gallons. I used to use it for GFO, now it just sits on a shelf storage. It will process 132 gph of tank water.

Instead, I use a mesh bag. In my reef system, the mesh bag with 2 cups of GAC thinly spread sits in a tray where ALL the sump flow MUST go through. In my predator tank system, the mesh bag lays between two baffles, thinly spread but occupying that whole space, so All the flow MUST also go through carbon.

So, the mesh bag processes 900 gph while the more expensive NextReef MR1 only processes 132 gph.

I can replace the MR1 pump with a 900 gph pump. However, given the smaller volume within the reactor compared to the sump volume, the carbon will get pulverized. It all depends on how you set it up, but a mesh bag CAN be 9X more effective than a reactor.

Essentially what you've done there is just create a "reactor like" situation, and while I will agree that that this can be a reasonably effective solution, it won't be as effective as a reactor. Let me explain:

The effectiveness of carbon filtration is NOT related to the rate at which water moves accross it, but rather the amount total amount of carbon surface area the water comes into contact with. Carbon extracts a certain fraction of organics (related to exposed surface area), from a certain volume per time. If you double the flow rate, you double the volume, but cut the exposure time in half, making it essentially a wash, so flow rate really has very little to do with the effectiveness of carbon (within the realm of normal cases, of course at a flow rate of 0 the carbon will have no effect).

The name of the game is just letting the tank water see the most surface area of carbon to get the greatest fractional extraction of organics per unit time. A reactor is very good at this -- it lines the carbon up in a column so all of the water must pass through a settled bed of carbon with no "shortcuts" through the media (a process called channeling). This forces the water to see the maximum surface area of carbon. When you wedge a media bag between baffles, it may look like all of the water must pass through it, but you don't get a good settled bed like you would in a reactor, opening up the possibility of "channeling" and areas of shorter length through the carbon. Water will preferentially go through these areas (there is less resistance) which means per unit time, your water will have fewer organics extracted from it.

Again, I'm not saying that it's not a reasonable way to do things, it's just not the BEST way to implement carbon.

Originally Posted by coralsnaked

Activated carbon will also remove the trace elements and minerals that are important to your fish and often leaches phosphate into the aquarium. Therefore running GFO in addition to carbon usually is a no brainer and additional supplementation of trace as well as major foundation elements can be needed.
Merry Skerry

This is not really the case. I've heard it said over and over again that carbon can remove trace elements, so it is a commonly held notion, but the thing is with very few exceptions, the trace elements required in reef tanks are small inorganic ions, and GAC isn't very good at removing those. GAC is tailor made to remove medium to large greasy, hydrophobic organic molecules (as opposed to small, hydrophilic, charged ions). Also, while carbon does add some phosphate to the water, the amount it leeches is really insignificant to a reef tank. While I certainly advoate using GFO, the amount of phosphate added to your water from fish food is on the order of 100-1000X greater than that which comes from carbon. Please see this article by Dr. Randy Holmes-Farley for confirmation: http://www.advancedaquarist.com/2012/3/chemistry

as always, just trying to help!