I hooked up the reactor and did a PO4 test before I turn on the reactor. I used APC test kit and the reading was 2.0. I used 19 tbsp of granules. After about 24 hours my reading this morning is -0.25 said:Just remember if you shut off the reactor, you'll have to clean it out and replace the media before you re-start it -- otherwise the lack of water flow will cause anaerobic bacteria to start consuming any dissolved organics, and you'll have a huge hydrogen sulfide build-up, which (in addition to smelling awful) will kill the tank if you pump it back into the tank water.
Just remember if you shut off the reactor said:Everytime I shutoff the reactor, I have to clean and replace the GFO granules? How long can I shut down the reactor before bacteria start to build up?
Everytime I shutoff the reactor said:This really holds true for any sealed water that you interrupt the flow to -- canister filters, media reactors, etc. -- even sealed pieces of plumbing (a return line with a ball valve for example). There's no real hard and fast rule as to "how long", as it depends on how much organic material is trapped in it and how much dissolved oxygen is in the water, but generally speaking any more than a few hours gets real chancy for something with a lot of surface area like a media reactor. If you open the reactor up and can smell any hint of rotten eggs (hydrogen sulfide), then it's been too long.
For some media, you can possibly rinse the media off very, very well (along with the reactor, tubing, etc.) and get away with it; I don't know how practical that is with GFO, since (if I remember correctly) GFO will adsorb some hydrogen sulfide.
If you need to shut the reactor down for awhile and want to re-use the media, open it up, remove the media, and spread it out in a dish or something (wet or dry) until you're ready to re-use it.
I'm thinking about ordering one of these this week. BRS states you can use both carbon and GFO at the same time. How does it work in this unit? Do you mix both together or is there an inner membrane that holds one of the media and you put the second media on the outside of the membrane? Thanks said:Nope, no inner divider of any kind (unless they've changed them recently or started shipping them with an extra piece of foam); you can mix them in the same cartridge, but that means you'll have to be replacing them both together. With the dual unit, of course, you can do them separately, and you can also arrange the GFO with some "headroom" to allow it to tumble, while keeping the carbon tight between the foam at top and bottom.
The "cartridges" are more or less the same as a refillable DI resin cartridge for an RODI; just a plastic container with a screw-off bottom and a piece of foam to go at either end of the media to hold the media in.
Gotcha said:Ideally, you want the GFO to tumble a bit, while you want to keep carbon fixed in place since it'll break up tumbling, so you lose a bit of efficiency there, but it's still way more efficient than just tossing the stuff in bags in your sump, so it's not a terribly big deal.
Particularly if you're tight on space, consider ordering a handful of the 90 degree elbows from them when you get it. The half-inch RO style tubing with the reactor is great, but it's really, really stiff, and hard to get positioned just how you want it; with the elbows, you can get a lot more control over the layout (albeit at a loss of a bit of head pressure, but probably not a problem, particularly with just one cartridge).