Carbon filtration question

[reedman]

I know we have discussed carbon use before and I don't want to rehash it all. What I am curious about is this:

Is it more efficient to use carbon passively or by forcing water through it?

If forcing water through is the most efficient (I think it is), at what rate does it become too much flow? Is there a maximum flow before you lose the benefits of running the water through the carbon?

How long does the carbon remain effective at removing chemicals from the water column?

Is there a ratio of carbon to water volume?

Thanks for any and all opinions and especially info backed by either science or experience.

-Reed

 

[snobanker]

Tagging along, because I am considering using a phosban reactor to run "forced" carbon

 

[snobanker]

Bumping this up to see if life can be breathed into this thread

 

[wrightme43]

I dont know for sure. My thoughts on the matter I can share. I think carbon would be more effective with water forced thru it. I mean if I just set a bag in the sump vs. setting a bag inbetween the baffles. I believe the one in the baffles will do more. On how long it lasts, I have read that if you wanna know for sure how its doing take it out, stick in in a bowl of the water it came from and put in a couple of drops of food coloring. It should be clear in just a few minutes. If not its exhausted. I have never tried that and only read it. I use kent marine reef carbon every once in a while. Its more of a judgement thing than a strict regiem for me. That is how I use it. I like the kent because it is peletised, and not washed in phosphoric acid. It also does not make alot of dust, and it really sizzles. I use it in a seachem nylon bag with reclosable tie strap. Steve

 

[mojoreef]

Agreed running fluidising it is the mest methods for all products like that, it allows all surfaces of the product to be exposed to the water at the same time. Contact time is always an issue, the longer the contact time the better. As per how long does it last that really depneds on the organics and such that it is exposed to, so different for every tank. Steves test sounds like a good one.
For me I just run it once in a while, usually after a cleaning. I do have a carbon canaster on the skimmer but thats more for burning off the excess ozone.


Mike

 

[NaH2O]

How about rinsing the carbon prior to use? Is it a standard thing that carbon can leach phosphates or is this a myth? I remember being told that long ago, and I don't remember researching as to why?

 

[Boomer]

Is it more efficient to use carbon passively or by forcing water through it?

Actively (forcing)

Is there a maximum flow before you lose the benefits of running the water through the carbon?

Yes, it depends on break through flow point, which is a function of the type of filter you have it in.

How long does the carbon remain effective at removing chemicals from the water column?

It is most efficient the firstday or two days, the it is down hill

Is there a ratio of carbon to water volume?

It depends on the load

My thoughts;
I would go 2 weeks, remove it and with it a mess bag beat on it with your fist, at the same time rinsing it. This exposes new surface areas and lengthens the live of the carbon. Reuse that carbon and leave in for 2 more weeks and then trash it.


There are many factors that often need to be taken into consideration when using carbon.

1. grams of carbon /liter of tank water or tablespoons / liter
2. flow rate of water through the carbon
3. how polluted is the water, and/or what is one removing
4. carbon type, ie., lignite, bituminous, etc.
5. particle size, ie., 2mm, 4mm, 8 mm, etc.

In general, most carbons in an active method, would remove a test dye, by 80 %, in the first 10 hrs. But IMHO you really can't go by this, for general carbon use, as is is not removing just dyes from the water. Some use allot of GAC, while some only small amounts 1 cup / 100 gals. I used a whole liter / 50 gals

How about rinsing the carbon prior to use?


Yes, always the most important thing is to remove all the trapped gases


Is it a standard thing that carbon can leach phosphates or is this a myth?

True if you go buy S_hit carbon, false if you buy good stuff. Even with the S_hit stuff if you rinse it almost all of the PO4 will be gone. It is easy to test fresh GAC for PO4. Put a half teaspoon in a glass of RO/DI and then add some PO4 indicator. If the GAC has PO4 the water will turn blue, the bluer it is the more PO4 there is. If it shows + then rinse it in and try again.


I remember being told that long ago, and I don't remember researching as to why?

Shame on you Nikki

If you all use something like Marineland's Black Diamond you will be safe

 

[reedman]

Holy Crap Boomer! Great info! Where were you back in December when I posted this? Oh well, then info is here now and I will put it to use.

Thanks!

 

[jlehigh]

Excellent and concise break-down Boomer! I bought the Kent Carbon in bulk because I could not find Black Diamond in anything bigger than a jar and I run way too much carbon on my 300gal to afford that...

 

[snobanker]

Now thats what I was hoping for...glad I bumbed this. OK so Fluidizing seems to be the way to go, and high quality helps prevent leaching PO4...so now for the tough question, what is the best carbon to use?

 

[Scooterman]

I'm trying to get a fluidize reactor so i can run carbon & rowaphos when needed, aint easy finiding a good one lol.

 

[tamarindthai]

sandwith carbon and phosgard in the same chamber ,,is it the good ideal?,, and which one first carbon or phosgard.thanks

 

[kent e]

Just wanted to bump this to let you know this info is helpful 2.5 years later.

 

[dnjan]

sandwith carbon and phosgard in the same chamber ,,is it the good ideal?,, and which one first carbon or phosgard.thanks

I don't know if I would sandwich them - in the past I have put them in separate filters set up in series.

You always want the carbon before the phosphate absorber. Most phosphate absorbers also absorb organics. But they are much more expensive than carbon. So why waste your phosphate absorber on organics. Carbon first, then phosphate absorber.