Originally Posted by bavass
so I have changed 30g of water since I put the reactor in. I started trying Reef Crystals, cleaned a small portion of my sand bed. ...
I think that's great that you're taking a big chunk out of your nitrates. What you're doing though is what I see a lot of people do when they're trying to troubleshoot - they change a whole bunch of things all at once. If you really want to narrow down where a problem is coming from, you have to make one change at a time and be patient to see the results. Your reduction in nitrates could be from the water changes, the salt change, the sand bed cleaning, the Seachem product... or a little of all of them. However it happened, it's a good thing, but it doesn't necessarily mean that the denitrate media was responsible for it.
From my understanding, the denitrate product acts as a quasi-deep sand bed in that it houses the anaerobic bacteria that convert nitrates to nitrogen gas. However, it takes a while for those bacteria to build up and kick in to gear. It would surprise me if it was responsible for the dramatic decrease in nitrates you showed over the first couple days.
[Edit: I just read your thread over on the Seachem forum. Didn't realize you were sucking out major portions of your sand bed. I thought you meant you were just vacuuming the surface. I don't think that's too good of an idea, but to each his own. Keep an eye on your ammonia levels, just to be safe. With the deep disturbance of the sand bed, I wouldn't be surprised if your nitrates start increasing in a week or two.]