Sulfur denitrator experiment

[andresont]

If i could only have as much patience, determination and drive as you do!
There are like gazillion people watching this...
How about we do a mass consciences experiment and visualize the following:
All test kits are accurate
Denitrator is working properly
And nitrate monitor comes back very soon in perfect working condition !

[Psyire]

On day 9, what did the salifert test kit show? Still 25?

[Delphinus]

Didn't get a chance to test with the other test kit, by the time I got around to the testing I had only a few minutes before the tank lights turned off, and the (as yet undeveloped) basement is too dark at night without the tanks on. You're absolutely correct though in that I need to do both testkits at once and do a side-by-side comparison to try to makes heads or tails of this.

What's weird though is that my nitrate/nitrite litmus test strips that I was using previously to tell if there was nitrite or not, are not registering any nitrate or nitrite, three tests in a row now where a strip has been dipped and there's been no colour change on it. It is an old set of test strips though, so more than likely the explanation for this one is they finally hit their expiration and I should just toss the rest.

I should be doing the testing at high noon and comparing the test tube colours outside in full sun. I bet then I'll get some lower #'s!

[Delphinus]

Okey dokey. End of day 10, got a chance to go a little test crazy:

Tank water:
Salifert NO3: could be 25 or could be 50
Elos NO3: darker than 50 but lighter than 75
pH: 8.2

I'm going to split the difference and call it "50ppm NO3" in the tank.

Reactor effluent:
Salifert NO3: 50ppm
Elos NO3: >75ppm (chart only goes to 75, it was darker than the 75 reference)
Salifert NO3: >= 4ppm (chart goes to 4.0, was at least as dark as the 4.0 reference, I think it was pretty close actually)
pH: 7.6

Soooo ... my interpretation: The Elos nitrate test kit is thrown off by any presence of nitrite in the test water. Reactor is definitely not cycled at this point.

I'm not sure if this is a good idea, but I shut off the feed altogether tonight and am just letting the water cycle through the sulfur with the recirc pump. If the problem is too much O2 in the feed water preventing a cycle from forming then this should help with that.

I still do wonder if the LSM media is somehow not as good as maybe some other choice. The Midwest Aquatic media that comes with bacteria preseeded, for example, or maybe winemaking sulfur is somehow a more pure grade, or something like that.

[Delphinus]

Sorry that this is such a long thread.

Day 14:

NO3 - 75ppm (Salifert, not going to bother with Elos until the NO2 is gone)
NO2 - 2.0 ppm (!! )

I have the flow cranked way, way back. Like 1 drop per 5 to 10 seconds.

I really do hope I'm seeing a reduction in nitrite and not just wishful thinking. Will test again in a couple of days. I figure at this point there's no benefit to testing every day, but maybe 2x or 3x a week until I see the NO3 drop.

[Psyire]

Glad to hear some good news. The other day I stumbled upon someone saying that it can take 6-7 weeks for an unseeded reactor to establish the bacteria in some cases. (depending on conditions and nitrate levels in main tank) Can't remember where I read this though...

[Delphinus]

Day 21

NO2 still >2.0ppm. Didn't bother testing NO3.

This makes watching paint dry seem exciting. I know I need to be patient but the lack of a visible trend in the #'s really does concern me. Is nitrite reducing bacteria really that hard to get to colonize?

I wonder if I have bad expectations. Is it possible the sulfur won't colonize nitrite reducing bacteria? I.e., should I just increase the flowrate now? Flush out the nitrites and let the remaining bacteria (hopefully there is some by now) just reduce the incoming nitrate?

This is far too complicated. All I end up with is questions and more questions and no real grasp of what you're supposed to be doing.