Running Carbon - How much is too much?

[Beverly]

Originally Posted by smokinreefer

is it not true that carbon will begin to leach the very same substances it is absorbing if left in a system for too long?

I've read the same thing in several places, too. Another reason I don't use it in any of our reefs.

Originally Posted by smokinreefer

oh yeah, i run carbon ocassional...for a couple weeks at a time. especially after choppin up softies, or when the water gets a bit discolored.

Why do you think your water get discoloured? Mine hardly ever gets discoloured, though when it does, I turkey baste the tank, let the water clear overnight, then clean the foam in the prefiltered 802.

The only time water discoloured in any of our current tanks, was in the 42 when a coral had had an accident (coral from above fell on it) and it began to die. Removed the dying coral from the tank, but the water clouded for the next couple of days, even though water parameters showed no ammonia, nitrite or nitrate. Turkey basted the tank 2-3 times, always cleaning the foam in the prefilters, and the tank cleared nicely.

[StirCrazy]

There is a comment misconception of Carbon and that it will leach all the stuff it took out back into the tank.

This came from the fact that low-grade carbons will release a tiny bit of what they have collected if you leave them in for an exceptionally long period of time.

In my freshwater tanks I have been using carbon for over 20 years now and I run it the same way as my salt water tank... 24/7 and change it once a month (sometimes every couple months if I forget it is in there )

If you have ever read about the renewing process for activated carbon you will see that yes you can get all the nastiness back out and use the carbon again, but doing this requires temperatures that I would hazard to guess most people can't simulate at home. Because of the requirements needed or remove the impurities from carbon it only makes since that it will not be able leach back into the tank.

Well never say never, so lest say that maybe it could leach back 10% of its uptake after 1 month, for the sake of argument. So if you change every month you are still removing 90% of the nastiness.

Now Personally I think 10% is high and I feel the actually number would be more like 0.5 - 1% but I used 10% for the example to show even if it is that high it is really not a problem.

so if you want to be safe use good carbons, this dose not mean expensive either, there are good carbons for cheep at other "non-fish" stores that are about 1/5th of the price.

Steve

[Troy F]

I don't know if the question is whether or not it will leach phosphates or nitrates back out but that it will continue to take trace elements out after it's plugged with the organics we are trying to remove. This is probably a moot point if you do lots of water changes but I'd still consider it.

[smokinreefer]

Why do you think your water get discoloured?

well a few things...
i have a fair bioload and can tend to feed quite heavily at times...
my skimmer works, but is not top notch...
when DOM build up in my tank, it is seen more easily, cuz i use 400W MH 6500k iwaski bulbs which will tend to show the yellow in the water a lot better than other lights!

i also think that sometimes the discoloration is just the way my eyes percieve the color, due to the combination of algae on glass, color rendition of the tank lights, color of the ambient room lights, and color of ambient natural light. i beleive this b/c sometimes, even if the tank glass looks clean, if you still scrape it, it makes the tank look so much nicer. also as i look at the tank throughout the day, sometimes it looks a bit yellow and sometimes it looks a crisp white.

but, i have decided to up my water changes as part of my regular tank maintainence

[Bartman]

I don't remember where I read it but I'm pretty sure that Carbon loses most of its effectiveness in a very short period of time (like several hours) . It will continue to remove undesirables after that but at a significantly reduced rate. The suggestion is that Carbon should be run periodically, as needed.

[Jack]

Originally Posted by StirCrazy

if you want to be safe use good carbons, this dose not mean expensive either, there are good carbons for cheep at other "non-fish" stores that are about 1/5th of the price.

Steve, can you point us in a direction of where you can get cheap carbon? How do you know if a certain carbon is "good"? Just curious.

Originally Posted by smokinreefer

as i look at the tank throughout the day, sometimes it looks a bit yellow and sometimes it looks a crisp white.

Shao, I totally know what you are talking about. I use the Iwasakis too and sometimes the tank seems a bit yellow but then I look at it awhile later and it's really light blue and whiteish. Darn bulbs playing with my eyes!! I use VHO too but it seems to "change" on me, I think its just me But I'm glad you mentioned that so I feel a little less crazy

[StirCrazy]

Originally Posted by Bartman

I don't remember where I read it but I'm pretty sure that Carbon loses most of its effectiveness in a very short period of time (like several hours) . It will continue to remove undesirables after that but at a significantly reduced rate. The suggestion is that Carbon should be run periodically, as needed.

yup, you are right, usaly 3 days to 1 week would be the amount of time in which the carbon will use up about 70% of its effectivness.. then the rate slows down.. it still removes stuff just much slower.

Jack, look at the container at walmart.. then go to a fhish store and look for the container that is the same shap, same color, but different name..

Same stuff just repackaged for wally world.. at a 1/4 to 1/5th the price

Steve

[Jack]

Thanks Steve, I was wondering about that Walmart carbon. Seems cheap, good tip.