questions on carbon ??
- Thread starter jetchris
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Thanks Bryan. Just throw me some rep in the future sometime
. I just got sick of guestimating on amounts of GAC and GFO to add so I researched the crap out of it the other night. It came in handy . Nice suggestion btw for actively forcing water through the carbon without a canister! +rep for you!Chris: Here's the info on reactivation of the purigen. Honestly, I'm not completely sold on the purigen... Although I haven't heard anything bad about it... I need to research it some before I start using it since I don't even know what its made of or anything about its effectiveness. I'd also be a little concerned with reactivating it and throwing it my sump since I don't have a chlorine test kit.
I'm sold on the be
<span style="color: black;">I have someone that left me a negative feedback because I suggest leaving carbon in the sump as substrate.:boo: Well, why does it “pains your</em> head?”</span>
<span style="color: black;">Let’s get technical </span>
<span style="color: black;">First off carbon doesn’t absorb anything. Unlike a sponge and dirty water relationship (or water with NH3), where water and sponge physically becomes one until something happens. Hence, if you dip the dirty sponge back into clean water, you can bet the surrounding will get dirty. </span>
<span style="color: black;">This IS NOT THE CASE WITH ACTIVATED CARBON. The system, in this case is the carbon, does not absorb anything including water. Carbon is impenetrable under normal circumstances. What carbon does is bond other things to its body with its pores, ridges, hooks etc. That is why carbon adsorbs/traps larger organic molecules-such as organic toxin or NH4 (depending on the carbon you use, some will trap big organic molecules, some traps smaller ionic/molecular molecules). There are theories that carbon attracts certain things to bond with itself (activated carbon do have certain chemical attractions that never change in reasonable time). </span>
<span style="color: black;">A pound of high quality carbon can have the surface area of a football </span><span style="color: black;">field. Since most of the pores are deep and anoxic, bacterial growth in this football field could do some good for you tank. The bond that carbon has with other chemicals is pretty strong. Under normal conditions the junk that is stuck to the carbon don’t wash off easily (that’s why it’s so painful to recharge it). However, if the carbon is packed to the max, whatever it cannot accept is just left in the water; a very insignificant amount is ever leached out unless you introduce the system to a radically different surrounding, but then the bacteria die also. </span>
<span style="color: black;">So leaving carbon in your sump will probably do more good than harm, with the condition that you use it for the purpose of anoxic decomposition and limited absorption. Bacteria will keep working even when the cleaning power is gone in 10-20 days. :thumbs: </span>
I guess I can get under peoples skin from time to time
<span style="color: black;">Let’s get technical
</span><span style="color: black;">First off carbon doesn’t absorb anything. Unlike a sponge and dirty water relationship (or water with NH3), where water and sponge physically becomes one until something happens. Hence, if you dip the dirty sponge back into clean water, you can bet the surrounding will get dirty. </span>
<span style="color: black;">This IS NOT THE CASE WITH ACTIVATED CARBON. The system, in this case is the carbon, does not absorb anything including water. Carbon is impenetrable under normal circumstances. What carbon does is bond other things to its body with its pores, ridges, hooks etc. That is why carbon adsorbs/traps larger organic molecules-such as organic toxin or NH4 (depending on the carbon you use, some will trap big organic molecules, some traps smaller ionic/molecular molecules). There are theories that carbon attracts certain things to bond with itself (activated carbon do have certain chemical attractions that never change in reasonable time). </span>
<span style="color: black;">A pound of high quality carbon can have the surface area of a football </span><span style="color: black;">field. Since most of the pores are deep and anoxic, bacterial growth in this football field could do some good for you tank. The bond that carbon has with other chemicals is pretty strong. Under normal conditions the junk that is stuck to the carbon don’t wash off easily (that’s why it’s so painful to recharge it). However, if the carbon is packed to the max, whatever it cannot accept is just left in the water; a very insignificant amount is ever leached out unless you introduce the system to a radically different surrounding, but then the bacteria die also. </span>
<span style="color: black;">So leaving carbon in your sump will probably do more good than harm, with the condition that you use it for the purpose of anoxic decomposition and limited absorption. Bacteria will keep working even when the cleaning power is gone in 10-20 days. :thumbs: </span>
I guess I can get under peoples skin from time to time
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Sorry carbon does not absorb NH4 from my understanding. You need to keep in mind that GAC will form three different types of bonds with different pollutants. The most common are the weak electrostatic bonds, they are attracted by Van der Walls forces, and this process as Jeremy and now you have correctly stated above is called adsorption. This is by far the most common type of bond in GAC where it forms weak bonds with large organic particles. What you fail to see though is that the weakly held organic particles are broken down rather quickly over time by bacteria and release inorganic nitrates and phosphates right back into the water that the GAC cannot make bonds with. This alone is one reason why we want to remove the GAC before this breakdown occurs en masse.
The GAC will essentially become a nitrate factory if you leave it in for long periods of time. Your hope though is that it has enough anaerobic zones for denitrification. Personally, and I think others will agree, its better to rely on your rocks/sandbed in the display and rocks in the sump take care of all your denitrification. I for one never have measureable nitrates anymore and I rarely change my water. Perhaps a "sandbed" of GAC particles would be a decent dentrification area. I dunno, do whatever works for you. I'd rather remove the GAC after its saturated with nasties from my tank. If you really need more dentrification so badly, put in some more rock!
I'm not trying to convince you, because you're too stubborn for that
. I'm just trying to put out additional info so people can decide for themselves.G'luck!
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<span style="color: black;">For me, I use carbon because it bonds to the pigments in the tank that skimming can't take out. Once it fulfills that job and can perform it no longer I remove it.</span>
This is a matter of symantics mostly. Used up carbon will leach ammonia, silicates, phosphates and a variety of other chemical compounds over time in reef aquaria. You can call it bonding, absorbtion, doodlie-do but the result should be the same. Is the beneficial possibility of carbon worth the risk... don't know but without some good scientific tests nobody can liklely say. </span>
My main point on this would be that as the bonded organincs in the carbon decay you are going to create ammonia. How much ammonia will a piece of carbon create, don't know but for me it isn't worth the time to figure it out.
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<span style="color: black;">For me, I use carbon because it bonds to the pigments in the tank that skimming can't take out. Once it fulfills that job and can perform it no longer I remove it.</span>
LAWL. Well i use it for my sump bed for bacteria majig. Some carbon leech stuff into the tank and some don't. If the carbon don't leech anything, then I don't think it do any harm leaving it there, because it don't put out what it didn't adsorb.
