Sulfur denitrator experiment

[Delphinus]

Day 6 Readings:

Tank pH - 8.2
Tank NO3 - 75ppm (Salifert)

Stage 1 effluent pH - 7.3
Stage 2 effluent pH - 7.6

Stage 2 effluent NO3 - 50ppm (Salifert)

Just to eliminate "testing error" (since I only did one sample for each reading above) I'll test NO3 again tomorrow using a different test kit. The original readings I took, were done with an Elos NO3 test kit, so that's what I'll use again tomorrow to see if I can confirm the apparent reduction already at this point.

Anyhow this is interesting stuff. Just under a week and the effluent coming out of the reactor appears to have a lower nitrate value than the inflow. The second stage, for buffering the low pH output of stage 1, does appear to have some function although not as profound as one might like (0.3 difference? better than nothing I suppose). Really is there a difference between dumping 7.3 into your tank versus 7.6? The drip rate is about 1 drop per 1-to-2 seconds so it is a very slow throughput.

[Psyire]

Nice results so far!

I would think the 2nd stg will work better once the bacteria is established in the sulphur stage... The difference in pH should grow as more and more CO2 is produced by the denitrifying bacteria.

[Delphinus]

Day 10 Readings (Thursday, forgot to post right away)

Tank pH - 8.2
Stage 2 effluent pH - 7.5 (didn't measure stage 1 effluent)
Tank NO3 - 75ppm? 60ppm? Had a REALLY hard time guessing how pink the reading was.
Stage 2 effluent NO3 - Hopelessly unreadable. Seemed like less but cannot be sure.

I hate test kits. Going to try again in a few days.

And I broke my vial for the Elos test kit so these were done with Salifert. Did I mention I hate test kits???

[Delphinus]

Unfortunately it's too late and too expensive to ask Santa for one of these, but how cool is THIS thing?
http://www.jlaquatics.com/phpstore/s...uct_ID=pp-mno3

Um .. eh heheh, anyone got one they'd care to lend me for a couple days???

Guess I know what I'm saving up for now .. next toy

[littlesilvermax]

Interesting. Our LFS, SWC, has had good success with denitrators.

FWIW I have a BB tank and a good skimmer and 23 fish including 5 tangs, and I feed two tablespoons worth a day and can never even get detectible nitrate readings in it.

I do get about 10 ppm in my coral QT though.

[Delphinus]

10ppm isn't too bad. I don't know if it's my ritteri or if it's something else. On this 115g I also have my Calfo-recommended-DSB-in-a-bucket (which is a joke BTW, don't ever bother trying one of these). Both were in a 90g previously ("both" as in "the ritteri was in the 90g and the RDSB was run on the 90g) and that tank too, also had chronic nitrate problems. (And when I say "chronic nitrate problems" I mean "readings very consistently above 30ppm". I'm not sure how I managed to let this tank get to 75ppm, I really let things slide apparently ) Whether it's the ritteri that puts an incredible bioload on a system, or the RDSB is itself a source of nitrate due to something or other bound to the sand itself, I can't say .. both theories seem equally plausible to me at this point. I would have to check my tank logs because this goes back quite a few years now, but I think that there is a pattern of whatever tank I keep my ritteri in, tends to have higher nitrates than my other tanks. But this could be coincidence, it could also be due to the fact that these have always been secondary tanks and as such, not running as high-dollar-value equipment as the primary tanks usually get.

My next tank will be BB altogether. I'm happy to hear the positive results with BB, very encouraging.

[littlesilvermax]

BB is just soooooo much easier and cheaper and easier and cheaper and you get the point.

[Delphinus]

Yeah, I get the point.

I had wanted to have "one tank with a little bit of a sandbed" so I could keep things like my open-brain and plate coral properly (I feel these guys do better on sand). Although at the moment I guess it's a moot point. I lost my plate coral when I was in Hawaii because the Tunzes buried it in sand and my tank-sitter didn't notice and it never recovered, and the xanthid crabs totally went nuts on my brain one day and it too never recovered. Now I have a cube tank with a bunch of rocks, a 20" anemone, and a dozen crabs. I can't keep nothing but the anemone in there and it .. sucks. I would like for it to be a softey tank one day but I have to figure out how to de-crabbify the tank, I can't *beleive* how many of them came in. The thing that really gets me is that I inspected *each* rock closely before putting them in the tank.

Guess this is turning into a bit of an off-topic rant now.. oops.

Anyhow I'm curious about things like sulfur denitrators and Zeovit. For me, to try this was $25 in ARM sulfur beads versus $300ish to get started on Zeo. Seemed like a no-brainer but I would still like to consider Zeo or Ultralith one day, but maybe in a few months once I get a couple other things settled first.

[Delphinus]

Day 14

An interesting and potentially discouraging development.

Tank NO3 - still @ 75ppm (guessing, the colour pink does not match any on the chart, going on a guessed intensity)

Reactor effluent NO3 -- instantly off the chart. The colour readings only go up to 100ppm and you're supposed to wait a few minutes for the colour to develop, but the colour was well past the 100ppm right away when the drops of the second reagent were added.

I'm not sure what the next step is. Is this the reactor just cycling? Or is it a failure? I don't know how much faith to put into this thing to guess how long I should wait before taking it off.

Feeling mighty discouraged ...

If I could make up 120g of SW I'd just do a 100% water change at this point. I don't know what to do.

[Psyire]

Check your reactor effluent for Nitrite, if it's still cycling then you should have a reading I would think.