Sulphur reactor not working, any help is appreciated.


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May 9, 2019
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I have since 7 months a nice sulphur reactor in my aquarium. It is a dupla nf500 small 2 chamber sulphur and 1 chamber calcium chamber. In the beginning I followed the instructions to start up the reactor. Had some difficulties making a constant drip (it always slowly decreased the drip) but after a 2 weeks it started to produce nitrite in the effluent and after 2 weeks more, the nitrate was 0 from the effluent. The nitrates in my aquarium were about 4. After having some troubles with the drip and installing a peristaltic pump, the drip was constant but the lowest drip possible was about 3 drops a second. Than the tube leaked in the peristaltic pump and I turned it off for some days (was maybe even a week). I restarted it with a new tube but the drip was again not lower than 3 drops and since than it stopped working. Now since 2 weeks I use the gravity as a feed to the reactor with a needle valve. The reactor was off for 2 days and than I started the drop with half a drop per second. The drop slows down over time but I adjust it every day. Now 2 weeks further it is doing nothing in terms of producing nitrite or reduced nitrate. My aquarium has now for some time about 40 nitrates. I do not run any skimmer in my system which is 175 l so about 45 gallon. Phosphate is controlled by algae growth and a refugium with cheato. Phosphates are near 0.
Is the sulphur just gone bad so there is no more denitrification bacterial growth possible? Any other possibilities for the reactor not working anymore?

Blue Spot Octopus

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Dec 30, 2016
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I know your frustration, nitrate reactors and calcium reactors can be a PITA, you need a really good peri pump that is adjustable and can run 24/7. Kamoer sells one, BRS has it for about 280 dollars. I have an old nitrate reactor and had the same problems as you, when I finally got it up and running something would go wrong and I have to restart all over again.

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