Jon, I do run a refugium, but it has no algae in it if that's what you meant. And it is a recent addition. I just never found carbon to do anything, however I use it just in case! I'm sure it does a lot, I just don't see it.
Now that I think of it, I do have a 5g tank running that is turning quiteyellow. It has 1 rock and 1 acro in it, so I guess a SPS tank can turn yellow.
Jamie, do you notice a yellowing of your water?

Brad, Yeah I have noticed yellowing in the past when I do not use the carbon. I did have a refugium with caulerpa in it at the time though. My point was more do to the fact that the corals seemed to be reacting to the increase in light from the polishing of the water via carbon. If one used carbon more frequently the water would stay cleaner and the once a month shock would less likely happen. If his water is yellowing before the monthly change then to me he needs to change in more often or try running more at once. Just as an example: I always try to go to the washroom before I start going. If I happen to be a little late it's harder to clean up after then If I took care of it in time :razz: Sorry for my poor attempt at humor. :lol:

Would this work?
 

Jon if I added an inline filter to one of my returns, do you think that would work? I have 2 1-1/2" abs returns from my tank. I could make an inline 4" filter that could be changed out quite easily. This would force about 1/2 of the water to be filtered. I could also have an overflow incase it backed up. Can you buy charcoal locally (just to test the concept)?

I also have a diatom filter I could adapt. I think I might have to try this. :idea:

Re: Some Carbon use/light intensity observations for ya.
 

I don't use carbon in our 2.5g, 7g, 14g or 42g unless something toxic has died and the inhabitants in my tank are suffering. Haven't had noticeable yellowing of the water in any of our tanks. Do water changes and complete filter/powerhead breakdown and cleaning in outgoing changewater weekly - WEEKLY being the key word here.

Clean the glass a couple of times a week. Have no skimmer, but turkey baste the sandbed, rock and corals 2-3 times a week to help export detritus. Geez, I better do that today after feeding :eek:

Did a couple of studies on carbon use in fresh and marine applications a few years ago. I was as scientific as I could be, but, really, I'm no scientist :smile:

The studies may be found at:

http://www.lostmymarblz.com/75gal-studies.htm

The Marine and Freshwater Carbon Study data were so complex that I did not complete the Observations or Conclusion parts of the study. I left those for any and all to discover for themselves.

Beverly, from what I read your study shows nothing. sorry but you were using different water samples and 1 hours is hardly enuf time for PH to stabalize . if you want to do it again, fill a large bucket with water. then do all your tests from that water. this way you have the same quality of water to start with. Next let the tank run over night to stabalize and do not treat with prime as by doing that you are adding other factors.
then you have to do your tests at the same time each day. as normal bacterial processes in a tank will varry the PH thought out the day but it should be close to the same value at the same time each day.


As for the origianl question, I use 8oz of carbon which I cange out every two weeks to 1 month. If I let it go a full month I do now a little less clarity in the water but only slightly. will this effect light penatration.. of course it will but as to how much it depends on the degree of turbidity. I am getting close to a month with out changing mine at this point maby I will let it go for another month and then do lighting tests at that time, then again 5 days later and see if there is a measurable difference.

Steve

Jon, its a long story from a few years ago. Just wondered about another carbon, like Black Diamond.

By the way, I run carbon 24/7. Always have. I change it when I remember. Either run it passive in the sump, {if I have one}, or in a hang on power filter.

Currently I have two medium sized carbon bags, about 3/4 full in a power filter. Usually switch one about every 3rd week.

Without a skimmer, I require it to compensate for my turf scrubber.

Hey Steve,

The tests ran for from 9 am one morning to 3 pm the next afternoon, not for one hour as you say, for Marine and Freshwater Carbon Study.

The tests for the Tapwater, RO and Saltwater pH Change Study ran from 9 am one day to 9 pm the following day.

Don't know if you read the studies wrong, but that's how the two studies were conducted. The use of various types of water was part of the point of doing the studies.

Also, used the equipment I had on hand, and I DON'T want to do those tedious studies again :evil: Maybe you're up to doing some research of your own and publishing your results?

HTH.

I am very intrested to see the results of these test Steve.

Jamie Now I see what you mean. That makes sense.

Ross, Sounds like a great idea as long as it's simple for you to make and change the carbon as well. As far as buying carbon locally I wouldn't. It's rediculously over priced here in the city. What I just got from j/l for $20 You would pay 40 to 50 dollars locally :rolleyes:

I was talking about the 1 hour you waited after filling the tank and turning on the equipment till the time you started your tests. sorry I might have typed it wrong.

Steve

[quote="StirCrazyI was talking about the 1 hour you waited after filling the tank and turning on the equipment till the time you started your tests. sorry I might have typed it wrong.[/quote]

Okay, I understand :smile:

In all tests, there is still the control tank of water using no carbon with which to compare the pH changes of tanks using various brands of rinsed and unrinsed carbon. I almost didn't use a control tank, but realized I would have nothing to compare the results to, such as they are. There seemed to be a marked increase in pH in the carbon tanks compared to the slower increase in pH in the control tank. My point is that, initially, adding carbon to a tank, there is going to be a leap in pH compared to a tank that uses no carbon.

The tests were done in small tanks, granted, and maybe not for a long enough period of time. (Unfortunately, I didn't have all day for days on end to put energy into making the study longer.) However, in a larger body of water the pH increase may not be as noticeable. But, then, in a larger body of water, more carbon might be used too. Six of one and Half a dozen of another :rolleyes:

Anyway, I did my studies in the fashion I chose because I was interested in finding out what actually happened when using carbon. Along with discovering the higher rate of pH increase, I also learned that phosphate is added to the tank from many of the carbon samples. Maybe not a lot of phosphate, but phosphate nonetheless.

I'd like to see other people doing experiments on whatever topics strike their fancies and sharing that information with the rest of us. We might all learn stuff we never knew before. That was my ultimate goal in doing my studies. And I DID learn things I didn't know before I did the studies :cool: