Sulfur denitrator experiment

[andresont]

Originally Posted by asmodeus

Tony do you have a pic of the reactor I would like to look at it for a sec..

http://www.canreef.com/vbulletin/showthread.php?t=28791

you can try first page of this tread for the pictures..

[Psyire]

I'm interested to hear what you think you've done wrong.

Not very encouraging results though... but perhaps there is a reason(s) that we'll find out soon.

I'm getting quite close to starting my own experiment, with any luck it will be late next week.

[seashells]

If you feel the nitrate readings are off then I would ask some other reefers to test your water. I had a salifert test kit and got off the wall readings. I compared it to a friends test kit and also the store where I bought it. I found after comparing I had to divide my readings by 2. So its possible your kit is inaccurate.

Doug

[Delphinus]

So, bearing in mind I haven't read the section in detail yet, only scanned it, these are the things that caught my eye:

- recommend upflow instead of downflow to avoid compaction
- recommend flow control valve on input not output to avoid pressurizing the unit
- recommend media volume 1% of total tank volume
- something about the reactor height to diameter ratio should be something like 5:1 (I'll have to read more about that one)

My main thinking here is that the flow-through is too high, and the recirc is not enough. I don't know about switching to 1% tank volume as that will need a different reactor, same with changing the height/diameter ratio (actually mine may already be close to that anyhow, give or take). The main thing I'm thinking is switching the flow control valve to the input, leaving the output wide open; changing the flow direction to upflow; potentially scrapping the feed pump (since need to slooooowwww it down even more), and upping the recirc pump from a mag2 to a mag7 or mag9.

[Psyire]

Your last 2 points revolve around a 1-pass reactor if I'm not mistaken. I don't believe T.R.A. Vol.3 discusses recirculating reactors. (therefore volumes and flow rates are changed)

I wouldn't increase the flowthrough rate of the recirc. chamber if I were you. This will nullify the 'O2-Free' zone if the flow is too much.

You may want to check your test kits as stated above, just in case something is off. I would just run a nitrate test on your new makeup water, during your next water change to see what it reads.

[Psyire]

If changing your flow through the sulphur chamber I would actually go the other way and lower it. This will create a bigger O2-Free zone and therefore more anerobic bacteria. If your flow is too high I would suspect that you would get into the middle of the denitrification cycle and not have enough anerobic bacteria to finish the cycle off. (which would seem to be what your test results are showing)

[Delphinus]

No indeed, I want to slow down the flow-through. Sorry if that wasn't clear. That's what I think that's my problem right now, in that there's too much flow-through, even at 1 drop per 2 to 3 seconds, it's too fast. There has been NO sulfurous scent and everything I've read said that a too-slow flowrate will have a scent, and a too-fast flowrate will likely still output nitrates and nitrite. A bigger unit would probably help but that's not what I have to work with so I have to find another means of controlling the flow through this and slow it down considerably.

What I do want to increase though is the power of the pump doing the recirculation inside the reactor. It won't work to increase contact time but I think there's not enough contact with the media in the current arrangement with the mag2.

I've been using three different test kits to take nitrate readings, unfortunately they all agree with each other. Although I only have a test-strip for nitrite, not a full-blown test kit for that, and no secondary testkit with which to compare results. Nitrite's not really a commonly stocked testkit it would seem (I'd never consider buying one if it wasn't for this).