Can I turn carbon reactor back on?
 

I turned off my carbon reactor for a week and I wondered if OK to turn it back on with the same carbon in it (changed it 2 weeks before I turned it off) or should I change it again with new carbon?

How big is the tank it is on? Unless it's quite a big tank, I wouldn't do it without boiling the carbon first.

I'm not tryin to be a dick or anything. But why? Would rinsing with R/O not be good enough?

because after that long without water running through it all the oxygen in the reactor will have been consumed and by now you've got a host of anaerobic bacteria in there that may or may not be producing all sorts of poisonous gasses and by-products. In a large aquarium it will all probably get gassed off and the bacteria will be killed shortly after you turn it back on, but if it's a smaller system you could end up dumping a bunch hydrogen sulphide in to your water, along with anything else that's built up as a result.

At worse, something bad will happen, at best, the carbon that's in there has been absorbing a weeks worth of gasses and metabolic wastes from anaerobic bacteria and it won't be as effective as it should be for how long it's been in your system. I'd just replace the carbon and start again.

I dunno, I'd rather have fresh carbon in there doing what I bought it to do than something that may not be effective anymore.

Carbon is cheap .
Get a new batch.

I agree 100%. Why waste time baking or rinsing something that is easy to change and cheap to buy.

I agree. Carbon is cheap, just use new stuff. That wasn't the OP's question though. :lol: I boil all new carbon, so if I'm going to pull the old stuff out and boil it, I would just put new stuff in there even if all it means is that I don't have to change it as soon.

Boiling will release most of the phosphate and nitrate out of it at the very least (carbon doesn't absorb any significant amount of phosphate, but any trapped detritus/fish food/etc would be in there breaking down), and will kill and rinse many of the bacteria out that won't survive when the reactor is turned back on. High temperatures always do a better job of "general" cleaning.

I do it with my phosban and carbon some times but I have a 300 gal so

Thank you all - I have a 90 gallon and the reactor is "dumping" in my 40 gallon sump. So just to be safe, I'll change the carbon.

Good call.