Yup. Im mixing Carbon and Rowa together in my reactor. Speaking of which, probibally time for me to change them too LOL

So you can run both in the same reactor not 2 reactors in series?

Edit: I just downloaded the installation instrctions from Two Little Fishies, in it they acknowledge that carbon and Phosban can be installed in the same reactor.

Two Little Fishes and Rowa Phos with an old Aqua Clear 30 powerhead.
Bag of carbon in sump.
I change the carbon more often than the Rowa so wanted it seperate.

how much rowaphos for a 55 gallon would be appropriate?

I just started using the GFO/Carbon reactor from Bulk Reef Supply. It uses refillable cartridges in an RO style filter housing. There is a single filter version as well that you can run GFO and carbon in the same cartridge.
With the foam in-between the GFO will tumble and the carbon doesn't.
They recommend a MJ-1200 for the twin version but I have it teed off the return line.
I think it's pretty slick, I was tired of fighting with the lids and connections on the Little Fishies reactors.
They have a video on their site showing how it works.
http://i4.photobucket.com/albums/y12...k/IMG_1376.jpg http://i4.photobucket.com/albums/y12...k/IMG_1373.jpghttp://i4.photobucket.com/albums/y12...k/IMG_1374.jpg

The instructions for Rowa Phos call for 100ml of Rowa for a 100gal tank, therefore 55ml of Rowa will be good. I usually add an extra 10ml as I loose some when I rinse it with RO water to get the finer particles out and reduce the initial brown water.

Yes, I was just eying that up on their website yesterday. If the carbon gets changed more frequently than the GFO would it be a messy process?

I would like to hang the single unit on the back of the tank. Does reversing the mount look like it would work?

It would be tougher to change just the carbon with the single stage cuz it goes in the cartridge first.
The bracket on the single stage looks like it will convert to HOB pretty easy.
My 2 stage has a regular RO type bracket but you could add a couple clips to hang it.