Test to see if I need to change my activated carbon

[daddy2kids]

Hey everyone. I looked for a Randy article on this, but couldn't find one.

Is there a test to determine if I need to change my activated carbon? Or a definitive span of time between changes? I am finding threads all over the map on timing of carbon changes, e.g., (a) change carbon every two days because of biofilm, (b) have two carbon packs in there and alternate every two weeks (I'm using a Fluval 305 with just carbon and GFO in there), and (c) change every month.

Also, is there anything I need to supplement when I do change activated carbon? Will my alk/calc dosing change? (I am using Randy's #1 from BRS.) Do I need to add anything, e.g., trace minerals or "coral vitamins" when I change carbon?

Thanks in advance!
Sean

[Allmost]

Hello Sean, you would have to test for DOCs, which we have no hobby grade kits for.

good read : http://www.advancedaquarist.com/2008/2/aafeature1

[bertoni]

As was stated, we don't have any useful tests for this purpose. After a month or so, the carbon likely is fouled by bacteria enough that it won't adsorb anything, so that's one way to time replacement.

Changing the carbon doesn't require dosing any additives or supplements.

[daddy2kids]

Thanks Bertoni. Thanks Allmost. (I was concerned that fresh carbon might have a relatively high absorption rate with respect to certain substances.)

Hey Salifert, if you read these, there is a new product opportunity here....

[tmz]

Typically, 4ounces ( 113grams) of a good carbon per 50 gallons of water volume changed monthly is sufficient. With rox carbon 2.6 ounces ( 74 grams) per 50 gallons is enough. Checking for bacteria clogging it up periodically is very helpful. I've run it 24/7 at those levels and change times for a number of years without any evident issues from depletion of trace and minor elements.

[daddy2kids]

Thanks very much Tom. Very helpful.

I infer from the article that Allmost linked that if I have let my carbon go for two months (i.e., wait an extra month before the change), I probably should change my carbon, wait three days, and then change it again (going back to monthly changes).

[tmz]

You are welcome,

Maybe, depends on the DOC in the tank ,the porosity of the carbon you use,whether or not it's blocked by bacteria build up and/or precipitation . Refreshing it 2x won't hurt; I might not do it just because I'm lazy and cheap.. Is your water yellowed at all? If not ,the 2 month old stuff may still be doing some work.

[Telaverus]

You're getting good advice from very experienced members here. I would suggest you find a routine and stick to it, barring any significant changes to your system. Keeping your carbon routine a constant will support consitency in your element levels that you will be determining and maintaining with regular testing and suplimentation.

[daddy2kids]

Nope. No yellow color at all. I had waited two months and changed it last weekend. The water didn't really look any different afterwards. Maybe you're right and another change this weekend would be overkill. Now that i think about it, there was really no goo at all on the carbon I replaced (years ago, when I used bioballs when my tank was FOWLR, the carbon would be covered in goo).

[Whitebeam]

'Coral Shop' produce a test which says it's for organics, although if you read the details, what it tests for is a little vague. No idea if it's any good or not. Some details here:

http://www.h2oaquatics.co.uk/test-kits-and-controllers/test-kits/coral-shop-test-kit-organics

Peter

[emooring37]

Moe had a test: use a small piece of white plastic (like a clorox bleach bottle) say maybe 1 x 3 inches. lightly color one side with a yellow crayon. suspend in tank and step back. if you can see the difference between the two colors, then you are fine. When you cannot tell the difference between the two colors, change your carbon. Hope that helps.

[philipph]

Typically, 4ounces ( 113grams) of a good carbon per 50 gallons of water volume changed monthly is sufficient. With rox carbon 2.6 ounces ( 74 grams) per 50 gallons is enough. Checking for bacteria clogging it up periodically is very helpful. I've run it 24/7 at those levels and change times for a number of years without any evident issues from depletion of trace and minor elements.

sorry for hijacking the thread,just wanted some more info on this.Im currently using seachem's matrix carbon at the amount seachem recomends for my 100 gallon tank which is 250ml or 3.6oz.I've read from several threads here that it is a bituminus carbon and inferior to BRS rox.Should I consider increasing the amount of carbon I use to what Tom suggests?would 8 ounces of this GAC be too much for a 100g tank?

[m2434]

I usually watch my corals and skimmer. The skimmer will tend to start producing noticeably more skimmate once GAC gets exhausted. Also, I find certain LPS corals will start to look a bit wilted. Usually within a day (typically less), the corals will perk back up and the skimmate production will decrease.

[tmz]

sorry for hijacking the thread,just wanted some more info on this.Im currently using seachem's matrix carbon at the amount seachem recomends for my 100 gallon tank which is 250ml or 3.6oz.I've read from several threads here that it is a bituminus carbon and inferior to BRS rox.Should I consider increasing the amount of carbon I use to what Tom suggests?would 8 ounces of this GAC be too much for a 100g tank?

Mililiters is a volume mesure. By volume 250ml is equivalent to 8.5 ounces. 3.6 must be the weight of 250ml the seachem product.. The recommended 4 ounces /2.6 ounces per 50 gallons is by volume.
Matrix is rated very well; near rox. So for 100 gallons 5 to 8 ounces by volume should do fine.

[philipph]

got it,thanks

[tmz]

You are welcome.

[daddy2kids]

Looks like my LFS might have the Coral Shop Organics Test Kit. If so, I will let you know what I find....

[daddy2kids]

Great suggestion m2434 about looking at my LPS! To specifically which LPS are you referring and what do you mean by wilted? For what am I looking?

I really like the idea of looking at skimmer output, but I don't think it will work for me. I have an AquaMaxx HOB and the impeller works itself out of alignment every 2-3 months, so I need to avoid the situation where both my skimmer is inefficient and my carbon is spent.

[vitodog]

Actually, Salifert does have a test kit to test activated carbon. I just saw it on Salifert's web site here in the sponsor forum.

[daddy2kids]

Uh, where is the Salifert forum? The Sponsor Forum seems to go from Reef... to Salt....

[vitodog]

Uh, where is the Salifert forum? The Sponsor Forum seems to go from Reef... to Salt....

On the home page (RC) click sponsors and you will find the Salifert web site, click and then click products. I just saw their advertisement for this product yesterday. I've not tried it so I can't comment on this product either positively or negatively. I'm just responding to the OP's inquiry.