Sulfur denitrator experiment

[Delphinus]

Today = February 13
Started = January 2
-> So exactly six weeks

Today's readings:
Tank = 30ppm (up from 23 two days ago again, it crept down over the course of the week until now)
Effluent = 23ppm, 2 drops per second

At what point does one accept that something is just not going to work? I don't know where to go from here. It's bad enough to see a lack of tank nitrate reduction but to see such huge inexplicable jumps is insult to injury. I haven't fed my anemone in weeks, the only thing I can think of is that I fed my ONE fish some NLS pellets and an extra pinch for the shrimp, but to see a 10 ppm increase overnight in a 115g? That has a skimmer and a denitrator AND a remote-DSB AND a chaeto growout AND some mangroves? Doesn't make sense to me.

[Psyire]

Compared to my setup I think that the Mag 2 is possibly too big for your application. A slower flow through your sulphur bed would create a more ideal environment for the anerobic bacteria. I'm running an eheim 1250 (a tad smaller than a Mag 2 for flow) on a much bigger reactor and it seems to be running great. Other than that, the only real difference between our setups is that I seeded mine with bacteria. (even though the CaribSea LSM is suppose to have some bacteria already seeded into it)

[Delphinus]

Update - I'm taking mine offline as soon as I have some time to get on my hands and knees to undo the plumbing and clean out the reactors and recover whatever media. In the meantime it's not hurting anything so I'm leaving it there but it's definitely no-good.

About two weeks ago I finally gave up hope altogether this would ever work out for me, so I decided I'd take it offline at the earliest opportunity (but left it on in the meantime since it wasn't hurting anything ... not doing any good, but not doing any harm, so I figured it could wait until I was looking for something to do).

Anyhow I stopped testing my effluent on Feb. 20. Sometime between then and yesterday the input line vapour locked and the siphon stopped so there was no flow. When I discovered this I did a nitrate test of the water in the reactor, and lo and behold I got (for the first time since NOVEMBER) a zero nitrate reading on the water inside the reactor.

So, I thought I'd give it one last kick at the can. Restarted the siphon and reset the drip rate to one drop per second.

24 hours later (tonight), the effluent is back up to 20ppm. (Tank is 35ppm.)

So ... I guess that's it. I'm done with this for now. My guess is that there's just not enough media, despite what people keep telling me that "its enough media" I think the numbers just tell a different story.

Psyire, how much media do you have in yours? Can you do a volume calculation? Even just a rough guess, like "1/2 container of LSM" or "3/4 container" or "2 containers" or whatever is fine. I'm just curious to see how it compares - you said your reactor was much bigger than this reactor so I'm curious as to how much bigger it really is.

[Psyire]

Sorry to hear....


But to answer your question.. 1.5 gallons (containers) of LSM. With a recirculation flow rate slighly lower than yours with the Mag 2. (this is where I believe your problem lies, but that's just my opinion) If you lowered your recirculation flow I think you would get closer to where you want to be. With a high recirculation flow I think you are getting oxygen present through your entire reactor. This is somewhat proven by your zero nitrate reading once your input was cut off.

I would be tempted to swap out that Mag 2 for a ehiem 1048 or something similar. Trust me, the results of lower nitrate are quite nice, as I have corals growing again that had stops for many months. It's made me a believer... so far.

[Delphinus]

You're probably right in that I should try a smaller pump, but I figure if I'm going to have to spend money to buy a pump I might as well also try a bigger reaction chamber because the small volume of media is really a wildcard I don't trust anymore. I could try swapping out this reactor for my calcium reactor and make this one a calcium reactor again or I could try to build something. I suppose I could try to find an Eheim 1048 or I wonder if I should just put a 1/2" ball valve on the output of the mag2 and set it to 1/2 or 3/4 to slow down the flow.

Oh well .. I went into this wondering if I could convert "this calcium reactor" into a functional denitrator, .. now I know the answer is "no - not this calcium reactor anyhow (but not to say one couldn't use another one)."

The next thing I want to work on is upgrading my G3 into a meshwheel and reworking the sump. I think it will be an interesting project. Maybe after that I'll look into trying the sulfur again, but for now I'm shelving the idea.

[Psyire]

Originally Posted by Delphinus

I wonder if I should just put a 1/2" ball valve on the output of the mag2 and set it to 1/2 or 3/4 to slow down the flow.

Why not do this before shutting the reactor down? It's a simple thing that may work perfectly... (and cheaply)

[Pansy-Paws]

Have you tried shutting the recirculation down for a few weeks to see if the media will seed more completely? I don't have recirculation myself, just a single pass through of the LSM (0.6% of the tank volume ... about 3 gallons), so I'm somewhat suspect of that component of the design simply because I've not used it myself. I do, however, have recirculation on the aragonite media to get the pH back up before re-entry into the tank ...

I've shut my unit down several times in the past six months, and during start up the key to reseeding is ultra ultra slow flow, and leave it there until you have a slight smell of sulphur (with your nose right at the outflow), then crack the flow up a bit (wait a few days for the slight sulphur smell to return), and repeat ...

The amount of sulphur relative to tank volume won't affect the zero nitrate formation (after all, the bacteria don't know how big your tank is), but with less volume you definately need slower flow, which can be a major obstacle. If I was to speculate without seeing your system, I'd say the flow is likely the factor that isn't correct yet and as a result, complete seeding of the media has not occurred. As well, if the length of the denitrator isn't at least five times the diameter of the cylinder, the drip rate would need to be even slower than usual to compensate and create the anoxic zone. I use a gate valve for flow control, but those can get spendy.

That zero reading you had would indicate that a super slow flow rate would give you success. For readings, I've found that the Jungle test strips aren't affected by the sulphur. Of course, you need to extrapolate between colours rather than simply reading from a digital device

I still swear by these devices for FOWLR systems with high bio load and heavy feeding.