Sulfur denitrator experiment

[Delphinus]

Still being somewhat suspicious of the #'s I tried testing again tonight using a different test kit. The first were done with Salifert, so tonight I tried with Elos.

I suspect that the Elos kits strengths are in the lower ranges. I took two test tubes side by side and did the input and output water together. I had to stare at the colours for a long time before deciding that one did indeed seem "less pink" than the other. The only sorta downer is that the pink matches more like 75ppm and 50ppm. I think I must be colourblind because I really have a heck of a time staring at pinks and trying to compare to the colour chart. They're all "fuscia" to me.

I talked to American Marine earlier today and I'm told that I'm the first one to call about any problems with their nitrate monitor. (Yay me! Go team!! Wooty!! ). Anyhow he gave me some suggestions but there really isn't a lot to work with (short of leaving the probe in the calibration solutions longer). The readings, if not clamped at over-range, are hugely fluctuating. For example tonight I got it to read anywhere from 30ppm to 100ppm to over-range on the 100ppm sample. I'm going to talk to them again tomorrow or Monday, hopefully we can get it working right or determine that it can at least be replaced if nothing else. I'd love to see what the readings are with something that can tell me real #'s as opposed to "in the neighbourhood of 50 to 75ppm".

[Delphinus]

Well ... I'm at a loss again.

At the end of day 7 I tested NO3 on the tank and the reactor output, using Salifert.

Tank - 25ppm
Reactor - 25ppm

I'm completely puzzled by this. Did the reactor start outputting at 25ppm earlier like I thought it might have been, and it's pulled the tank down to 25ppm in the days following even though the feed is super-duper slow?

Or is it more likely that the chaeto in the tank, which has suddenly kick started a growth spurt, has sucked up some nitrate?

So .. tonight (day 9) I test the reactor effluent with my Elos test kit.

You're supposed to add the reagents, then shake for 5 minutes to wait for the colour to settle. Well within 30 seconds the colour was darker than the darkest colour on the colour chart (much like before on trial #1), which in the Elos NO3 testkit is 75ppm. So the reactor is outputting >75ppm again? Huh? What gives? Does the Elos test kit colour actually fade in the 5 minutes unlike other test kits where it gets darker the longer you wait? Or am I messing up the testing? Or is the reactor outputting a super high nitrate for real and my Salifert test kit is out of whack?

I'm completely at a loss to theorize what's going on here.

The one tool I had hoped would help clarify things, the nitrate monitor I bought on Boxing Day, is seemingly defective, and has been sent to American Marine directly to troubleshoot and repair or replace if need be. In the meantime I'm out the $300 and I'm out the unit until it gets sent back to me. (I trust the issue will get resolved satisfactorily .. I'm not knocking the service I've gotten, I'm just disappointed I can't use the unit as a yardstick for my nitrate levels because trying to make heads and tails of these test results ... simply sucks!)

Gonna try rearranging my reactor feed situation and see what I can come up with. I'm determined to see successful results dadnamitall!!

[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.

[Delphinus]

I still wonder about the Caribsea LSM. I've read a few times where people say if their reactor clogged, that getting it going again you get a wicked rotten eggs smell in the whole house. I mean, I have to basically get my nose right into a sample of this water, sniff it as hard as I can, and if I use my imagination I might imagine a slightly sulfurous scent (ie., not even close to Banff Hot Springs kind of scent). Low grade sulfur maybe???

Apparently American Marine did find my NO3 monitor to be defective, it's on its way back to me. Hopefully it arrives soon and I can start using it to track nitrates instead of guessing-the-pinks.

I might as well try a coil denitrator at this point too, what the heck, eh?