Sulphur smell from pellet reactor

I-DOG

New Member
Hi guys.
So we purchased a tank second hand with a bunch of equipment including a bio pellet reactor. We have now come to wanting to set up the reactor but even after scrubbing, cleaning it out with vinegar and then RO water it still has a smell of sulphur. However the water we used to pump through it doesn’t smell at all so I’m guessing the plastic is impregnated with the sulphur smell.

I have read that pellet reactors can sometimes have this smell due to flow issues etc. Should we still be using it?
 

DaveK

Well-Known Member
The sulphur smell happens because the reactor in in an anaerobic state with little flow, so in addition to nitrates, the reactor was breaking down sulfates. This likely occurs because you moved an established system and there was no water flow through the reactor.

What you want to do is replace the media inside the reactor. Yes, that media is not exactly cheep. Discard the old media. That way your sure about the reactor.

Note that a bio pellet can be used as either an aerobic mode to reduce ammonia to nitrate or anaerobic mode to reduce nitrate. Depending on it's use, you'll set the flow high or low. The low flow rate setting used when using the reactor in anaerobic mode is much more critical.
 
  • Like
Reactions: SPR

I-DOG

New Member
The sulphur smell happens because the reactor in in an anaerobic state with little flow, so in addition to nitrates, the reactor was breaking down sulfates. This likely occurs because you moved an established system and there was no water flow through the reactor.

What you want to do is replace the media inside the reactor. Yes, that media is not exactly cheep. Discard the old media. That way your sure about the reactor.

Note that a bio pellet can be used as either an aerobic mode to reduce ammonia to nitrate or anaerobic mode to reduce nitrate. Depending on it's use, you'll set the flow high or low. The low flow rate setting used when using the reactor in anaerobic mode is much more critical.

Cheers for the reply that’s really helpful. The bio reactor isn’t in use at the moment (so it’s not the media which is smelling) and has been sitting empty since we got it. Planning on using it to reduce nitrates so I’m guessing we want it in the low flow mode. Does that mean that media should not be aggressively tumbling?
 

DaveK

Well-Known Member
The flow rate and pellet tumbling can be a little tricky to set up. I'd start the flow with the pellets just tumbling and then adjust it up or down as needed. Keep in mind that it can take 4 to 8 weeks to see the effect of your change, so don't mess with it very often.
 
  • Like
Reactions: SPR
Top