Questions about carbon particle size and passive vs. Floudized use

[pledosophy]

We read about carbon dust causing issues with fish. Does anyone know the size of the dust and what size micron would be needed to filter it?

Are there any studies showing the difference in effectiveness between passive (sticking carbon in a bag in a filter sock) or floudized (like a TLF reactor) use of carbon or GFO? Link please.

 

[Rx79394]

https://www.youtube.com/watch?v=UbLF1zgw8oQ&list=PLBaMLrfToJyybUT18OE3fMomFb9XU0ffC&index=24

Start at 5 mins or so.

Not quite a scientific study, but good enough for me...

I've been wanting to buy a reactor for a while now.

 

[fishome25]

carbon should not be fluidized. it is too soft and will grind to dust. I do tank maintenance for people and used to use GAC on all the tanks I serviced. tangs and angels all developed HLLE. I stopped using it and they never developed it again. I was always a skeptic that it was the cause but proof is in the pudding. I now use pelletized carbon.

 

[pledosophy]

bumpity bump bump

Anyone know the size of a carbon fine?

 

[Dan_P]

I don't know how more effective a fluidized GAC bed is, but here is some information and ideas.

A fluidized bed keeps the medium well mixed and all surfaces maximally exposed to the percolating liquid or gas. The medium needs to be resiliant to the physical jostling in a fluidized bed or else its size is degraded. Granular activated carbon is brittle and may crumble or chip in a fluidized bed. Even carbon in a media bag placed in a filter sock may be jostled enough to cumble if the flow is high enough.

An optimum approach would be a bed a of GAC with up flow (to eliminate air channels) just under fluidization speed. If you can jostle the bed or briefly fluidize it every so often to loosen any clumping, that would be a plus.

 

[skeeter_ca]

You would probably have to experiment with different sized filter socks to see where the carbon sizes stop going through it. I would start at 100micron, since I already have them and go smaller if that doesn't contain the dust. It would be simple testing it in a 5 gallon white bucket to see if the particles settle to the bottom. The hardest part would be find filter socks below 100 micron. I've never seen them, but I never look for them either.

However I do believe the added maintenance and cost would not be worth the extra efficiency you would gain by tumbling it.