I posted this on Facebook for my local reefing group, but I thought that it was interesting enough to share here.
I recently restarted a reef tank about 7 months ago, and have been reading up on various articles on reefkeeping to try to improve my success rate with keeping fish/corals/etc as well as my knowledge base. One topic that I didn't feel that I had a good handle on was activated charcoal for removing "organics" - how much to use, how often do you change it, and is there a way to determine organic levels in my tank specifically without too much fuss. The only article I found up until very recently was from Advanced Aquarist's 2 part article (part 2: http://www.advancedaquarist.com/2008/2/aafeature1), which still left me with questions as to how to apply those findings to my tank.
I then found Bulk Reef Supply's videos, with 1 in particular catching my interest - yellowing agents reducing PAR by up to 25% (which sounds pretty darn high to me), and a "2 bucket test" to visually inspect your own tank water for organics (http://www.bulkreefsupply.com/video/view/When-should-you-change-your-carbon-How-To-Tuesday/). The assumption that the removal (or persistence) of yellowing compounds is similar to the removal (or persistence) of undesirable organics seems reasonable to me.
I wanted an easier way to assess my tank water for color, so I bought a fluorescent bulb sleeve (clear) and a white PVC endcap from the local hardware store, cut the sleeve with scissors to a few inches shorter than my tank is long (so I could dip the whole thing in the top of my tank easily), and crazy glued the PVC cap onto the tube to make that end watertight.
I've run through 2 brands of activated charcoal, taken various photos with comparisons, and have some thoughts. Background - my tank is a Red Sea Reefer 170, 32 gallon display with sump, total water volume 43 gallons. I used both Red Sea activated charcoal (300 mL, pics not shown) and ROX 0.8 (300 mL, summary pic below). I have a finger leather and a toadstool leather, a variety of mushrooms and zoanthids, and some LPS with a few SPS. I feed roughly 1/2 cube of food, run the tank skimmerless, and have a refugium with dragon's breath and chaeto under a PAR38 bulb in the sump with another large clump of dragon's breath in the main tank. All activated charcoal is contained in a mesh bag in a good flow area of the sump. Bioload is a common clown, cleaner shrimp, and a Wheeler's shrimp goby. I had a Midas blenny who sadly jumped when I had the mesh lid off for coral rearrangement and didn't find his body until the next day.
Here's a sample picture of water colors (white balanced using ProCamera off of a paper towel, roughly 3K in each photo. My thanks to someone who pointed out white balancing to me for this) -
July 7 was when I thought my old activated charcoal was used up. I replaced it with ROX 300 mL (roughly 9 mL/gallon display tank volume), and July 8 is after roughly 12 hours. On 7/12, the water was yellowed similar to 7/7, so I removed the bag, and over the sink massaged the bag to break up any clumps and move the pieces of activated charcoal around as much as possible. I then rinsed it under tap water to remove any new fine particles and placed it back; 7/13 the water was nice and light blue like 7/8 again. Unfortunately, doing this a second time on 7/18 didn't work very well.
Also not shown - pics for my Red Sea carbon, which tells a similar story (may have lasted slightly less long, but in either case each bag needed manipulation after about 5-7 days to get back to blue water, and a second bag manipulation didn't do much of anything).
My take on this - activated charcoal at a dose of roughly 9 mL per gallon of display tank volume removes visible organic coloring agents for roughly 7-10 days in my tank, with the bag needing to be massaged at roughly the halfway point to maximize adsorption of organics. Assuming I buy ROX by the gallon at BRS, I can replace the charcoal 3x monthly at a rough cost of $11/12 monthly (or increase the volume so that I only need to replace it every 2-4 weeks), use carbon in bursts and accept that my water won't be blue and pristine the entire month, or try to remove things that generate yellowing agents (seeing as I'm trying to run a skimmerless macroalgae-filled refugium tank this seems impractical). I thought about using a reactor for activated charcoal (which in a different BRS video looks like it works more rapidly at removing agents), but since I had water clearing in under 12 hours and manipulating the carbon didn't seem to free up any more adsorbing capacity the second time around, I don't see an "effectiveness" reason to buy a reactor. I suspect that it would be more convenient, however.
While there are a variety of flaws and assumptions in this, the idea of monitoring tank water color as a marker for changing activated charcoal seems useful to me. I hope my experiments are interesting as well.
Any thoughts?
11-12
I recently restarted a reef tank about 7 months ago, and have been reading up on various articles on reefkeeping to try to improve my success rate with keeping fish/corals/etc as well as my knowledge base. One topic that I didn't feel that I had a good handle on was activated charcoal for removing "organics" - how much to use, how often do you change it, and is there a way to determine organic levels in my tank specifically without too much fuss. The only article I found up until very recently was from Advanced Aquarist's 2 part article (part 2: http://www.advancedaquarist.com/2008/2/aafeature1), which still left me with questions as to how to apply those findings to my tank.
I then found Bulk Reef Supply's videos, with 1 in particular catching my interest - yellowing agents reducing PAR by up to 25% (which sounds pretty darn high to me), and a "2 bucket test" to visually inspect your own tank water for organics (http://www.bulkreefsupply.com/video/view/When-should-you-change-your-carbon-How-To-Tuesday/). The assumption that the removal (or persistence) of yellowing compounds is similar to the removal (or persistence) of undesirable organics seems reasonable to me.
I wanted an easier way to assess my tank water for color, so I bought a fluorescent bulb sleeve (clear) and a white PVC endcap from the local hardware store, cut the sleeve with scissors to a few inches shorter than my tank is long (so I could dip the whole thing in the top of my tank easily), and crazy glued the PVC cap onto the tube to make that end watertight.
I've run through 2 brands of activated charcoal, taken various photos with comparisons, and have some thoughts. Background - my tank is a Red Sea Reefer 170, 32 gallon display with sump, total water volume 43 gallons. I used both Red Sea activated charcoal (300 mL, pics not shown) and ROX 0.8 (300 mL, summary pic below). I have a finger leather and a toadstool leather, a variety of mushrooms and zoanthids, and some LPS with a few SPS. I feed roughly 1/2 cube of food, run the tank skimmerless, and have a refugium with dragon's breath and chaeto under a PAR38 bulb in the sump with another large clump of dragon's breath in the main tank. All activated charcoal is contained in a mesh bag in a good flow area of the sump. Bioload is a common clown, cleaner shrimp, and a Wheeler's shrimp goby. I had a Midas blenny who sadly jumped when I had the mesh lid off for coral rearrangement and didn't find his body until the next day.
Here's a sample picture of water colors (white balanced using ProCamera off of a paper towel, roughly 3K in each photo. My thanks to someone who pointed out white balancing to me for this) -
July 7 was when I thought my old activated charcoal was used up. I replaced it with ROX 300 mL (roughly 9 mL/gallon display tank volume), and July 8 is after roughly 12 hours. On 7/12, the water was yellowed similar to 7/7, so I removed the bag, and over the sink massaged the bag to break up any clumps and move the pieces of activated charcoal around as much as possible. I then rinsed it under tap water to remove any new fine particles and placed it back; 7/13 the water was nice and light blue like 7/8 again. Unfortunately, doing this a second time on 7/18 didn't work very well.
Also not shown - pics for my Red Sea carbon, which tells a similar story (may have lasted slightly less long, but in either case each bag needed manipulation after about 5-7 days to get back to blue water, and a second bag manipulation didn't do much of anything).
My take on this - activated charcoal at a dose of roughly 9 mL per gallon of display tank volume removes visible organic coloring agents for roughly 7-10 days in my tank, with the bag needing to be massaged at roughly the halfway point to maximize adsorption of organics. Assuming I buy ROX by the gallon at BRS, I can replace the charcoal 3x monthly at a rough cost of $11/12 monthly (or increase the volume so that I only need to replace it every 2-4 weeks), use carbon in bursts and accept that my water won't be blue and pristine the entire month, or try to remove things that generate yellowing agents (seeing as I'm trying to run a skimmerless macroalgae-filled refugium tank this seems impractical). I thought about using a reactor for activated charcoal (which in a different BRS video looks like it works more rapidly at removing agents), but since I had water clearing in under 12 hours and manipulating the carbon didn't seem to free up any more adsorbing capacity the second time around, I don't see an "effectiveness" reason to buy a reactor. I suspect that it would be more convenient, however.
While there are a variety of flaws and assumptions in this, the idea of monitoring tank water color as a marker for changing activated charcoal seems useful to me. I hope my experiments are interesting as well.
Any thoughts?
11-12
