Should I Tumble GAC Or Not?

[BigEZ77]

Just set up a Minimax reactor with the best carbon I could find locally (Polyplab) and am wondering at what level should I tumble the carbon? I've done searches and find some people say not to tumble at all because it will break up and get into the tank while others say it should be tumbled at a very high rate so it gets alot of exposure to the water. Checked out some BRS videos and it seems they have it at a very light tumble so the whole stack is moving a bit, but nothing more than that. What's the best way to run it?

PS. A link to a video would be great if anyone has one, so I can see and match.

Thanks,

Russell

 

[BigEZ77]

While I'm at it, lol, is it best to have it directly after the skimmer before the returns in an AIO tank with rear sump? That's where it is now.

 

[jminick2]

no tumble carbon, Light tumble on GFO. that's how ive always done it.

 

[BigEZ77]

So it shouldn't move at all in a reactor? What's the point of a reactor then?

 

[homer1475]

Absolutely do not tumble GAC(Granular Activated Carbon)! It will grind itself to dust and pollute your tank.

GFO(Granular Ferric Oxide) should be set at a light tumble. It was always explained to me, "So the surface boils".

 

[jminick2]

The reactor is just a separate container for it so you don't have carbon floating around in your display.

 

[homer1475]

So it shouldn't move at all in a reactor? What's the point of a reactor then?

Your actually forcing water through the carbon, and not just passively around it.

This is a nice video by BRS and explains how and why you should run carbon in a reactor.

BRS 160 Reactors.

 

[BigEZ77]

K, I have set it to the lowest possible setting. Unfortunately I couldn't stop the top few pieces from moving but the column is not moving. Will check out the vid. Thanks for the help all.

 

[billdogg]

I plumb my carbon reactor so that the water goes down through it rather than up so that it cannot tumble - water pressure holds it in place.

hth

 

[homer1475]

I plumb my carbon reactor so that the water goes down through it rather than up so that it cannot tumble - water pressure holds it in place.

hth

+1
Since I read you can do it this way, I plumbed my new tank and reactor this way also. Super simple to just switch the inlet and output, and you don't have to worry about it tumbling and grinding itself to dust.

 

[BigEZ77]

Unfortunately I don't have that option but from watching the video Homer posted, I realized that I should be pushing the top sponge all the way down onto the carbon...about to do that.

 

[BigEZ77]

Ok, just did it. One more question...Should I have the flow wide open with the sponges (2) down on top of it to force more water thru? The carbon doesn't seem to move at all. However, I'm worried that over time the sponges might slide upward thus allowing the carbon to tumble again. The Minimax reactor doesn't have anything to hold the sponges in place unless I fill the reactor to its capacity but this would be too much for the size of my system. Also, my reactor is in the rear sump so I can't see what its doing without pulling it out. If ya'll think I'd be pretty safe to leave it this way then I will. Otherwise I'll turn the flow down. Thx.

 

[jminick2]

there is two sponges correct? If the flow is going up then put the sponges at the top of the reactor then it wont move....put the carbon in between the sponges

 

[BigEZ77]

There's two sponges on top and two on the bottom. Good idea, I'll try that tomorrow but I think I can only access the canister from the top. i.e. it would be very hard to pull the bottom sponges up unless the bottom piece comes off. Either way, I should have max flow if the carbon is held in place correct?

Worst case scenario, I can rig something to hold them in place the way they are now.

 

[morpheas]

The reason you tumble GFO is because it clumps together, it binds if left alone. Now what I do (and I picked that up from a brs video) is I mix some GFO with my carbon, not too much just enough to be kept separate from the carbon pieces so it doesn't clump (if I recall correctly brs video said 1/4 cup gfo 3/4 carbon but I just eyeball it). Doing that you can hold the mixture tight I.e. No tumbling and have maximum flow through it. You probably waste some gfo because you change carbon more frequently than you would gfo but it's a good solution so you don't have to have two reactors and fuss with flow rates. Good luck!