I've been meaning to post this for some time now, but haven't found the time...
For the longest time, I fought with nitrates. Months and months, water change after water change. :(
... I tried coil denitrators (two of them actually) - no luck :'(
... I tried a commercial product (essentially alcohol dosing) - no luck :'(
Finally, out of desparation - I tried a sulfur denitrator and... (drum roll please) ... It worked! It not only worked - it worked FAST!!! and has continued to work for several months now.
Now, I had the best of intentions when I built this. I said to myself, 'Take lotsa pictures Dave' - but I forgot :-[
So - I'll have to work with bush league MS Paint schematics instead (sorry :-[ )
Here is the unit itself - "Recirculating Sulfur Denitrator"
(https://www.ovas.ca/forum/proxy.php?request=http%3A%2F%2Fi298.photobucket.com%2Falbums%2Fmm270%2FZzippper%2FRecirculatingSulphurDenitratorSchem.jpg&hash=9b85b04e18eb8402083a6d0e8075e001c01f210d)
More improvements since I prepared this diagram:
- Instead of using 1/4" flexible polyproprelene tubing to deliver water to the input, use something larger. It will be less prone to clogging. I switched to 1/2" flexible polyproprelene tubing and it is completely clog free.
- You'll need a feed pump to pump water from your sump to the unit via the flexible polyproprelene tubing (MJ is fine)
- Flexible tubing from the output should remain 1/4" (easier to regulate flow) Route this tubing to the aeration chamber below. Regulate flow with a small ball valve (better) or an airline valve (less reliable than a ball valve)
- Don't forget the degassing output. connect to some 1/4" flexible polyproprylene tubing with a valve at the end. Use it to purse the unit of air/gas once every few weeks (and at initial startup)
FAQ's
- What does the sulfur do? - It provides a growth medium for bacteria that will consume nitrates (mmmmmm - Yummy!)
- What is the aragonite for? - After the water has been processed by the sulfur and bacteria, it tends to be a bit on the acidic side. The aragonite helps to neutralize the acid and produces a beneficial byproduct... Calcium is added to the water!
- What kinda recirulating pump should I use? - I tried a MJ1200 and found it quite noisy and too powerful - not to mention that standard MJ pumps are only supposed to be used submerged. A suitable replacement which can be used un-submerged is a MJ 400 Utility pump (can be purchased at Big Als Online) - although, I cannot vouch for how noisy they are.
This unit works great and can eliminate your nitrates in as little as a few weeks! I went from nitrates of 30-40 to ZERO in 3 weeks.
One small problem... The effluent (output water) from the unit can still have an undesireable pH of around 7.3-7.5
Easy fix - build the "Aeration Chamber" pictured below.
(https://www.ovas.ca/forum/proxy.php?request=http%3A%2F%2Fi298.photobucket.com%2Falbums%2Fmm270%2FZzippper%2FAerationChamber.jpg&hash=87b70a4d0dd39ccd4d08c2b71a7472829394bbd8)
The aeration chamber construction is pretty much self-explanatory. It's function is to drive as much oxygen into the water as possible as doing so will increase the water's pH to a more reef-safe level. Oxygen is also good for the reef inhabitants!
Intially run with denitrator with a very fast drip rate for the first 4-5 days. If you smell sulfur, speed up the drip rate. The output of the denitrator will have nitites for the first 3-4 days - you may want to drip this into a pail and dispose of it during this period. Test the output water for nitrite on the 3rd day and then everyday thereafter until nitrite reads zero (another day or two at most). The unit has now cycled. That's right... it takes 3-5 days to cycle (unlike coil denitrators which can take months to cycle).
At this point the denitrator water should be dripped into the aeration chamber shown above. Increase the drip rate at this point to a slow but steady stream. At any time, if you smell sulfur, increase the flow rate a bit. Check it again in a few hours, if the smell persists, increase the flow rate again. Repeat until the sulfur smell dissappears.
Once cycled, nitrates should drop to zero within a 3-5 weeks (depending upon how out of control your nitrates are). Test every 4-5 days and you'll see it drop pretty quickly. Once the nitrates reache zero in your tank, there will be a die-off of the excess bacteria in the sulfur denitrator unit (not enough nitrates left to feed them all) and the bacteria level will normalize to the level that is necessary to maintain your nitrate level at zero. This stage generally means the appearance of a sulfur smell again - increase the flow rate as described above until the smell dissappears.
One last tip. Try to keep water flowing to the unit at all times. If there is a power-outage (even just a couple of hours), the water dwells too long on the sulfur media. The result is merely a nusiance... the sulfur smell will return briefly - but only until the water in the unit has been purge/replaced by other water. Also, the output water will also appear a bit milky (bacteria bloom) - so your tank water may also look a bit milky. I suggest wet skimming for a day or two to skim out these excess bacteria.
Lemme know if you have any questions.
Z
Thanks for the effort of writing it up and sharing!
I still have the one you built for me but I took it off-line when I changed tanks. I should set it up again before the problems start.
Cool design, it's slim enough that it doesn't take up a lot of room, the only issue I had was algae growth in the input/output tubes from sitting in daylight but I wrapped the tubes in electrical tape which seemed to do the trick.
Quote from: FocusFin on May 05, 2009, 07:49:01 AM
I still have the one you built for me but I took it off-line when I changed tanks. I should set it up again before the problems start.
Cool design, it's slim enough that it doesn't take up a lot of room, the only issue I had was algae growth in the input/output tubes from sitting in daylight but I wrapped the tubes in electrical tape which seemed to do the trick.
That unit was actually one of my earlier
coil denitrator units. The coil based units were not cutting the mustard on my tank for some reason - so I gave up on them and went the
sulfur denitrator route described in this thread.
One work of caution Mike... If your coil unit has been sitting idle for more than a couple of days - it's gonna be nasty in there. The bacteria would have consumed whatever nitrate was present in the water and then died off. The smell will be... tremedous :o
If (big if) you plan on hooking it back up - you'll want to flush it out with fresh water for at least 4-5 days first. Fill a bucket with fresh water and hook up a pump to cycle the water into the unit and then back to the bucket. Change this water frequently. Keep flushing it until there is no more smell. Then re-flush it for a day or two with salt water. Once you re-hook it up to your tank/sump - it will re-cycle.
Z
Quote from: Zzippper on May 05, 2009, 10:19:29 AM
One work of caution Mike... If your coil unit has been sitting idle for more than a couple of days - it's gonna be nasty in there. The bacteria would have consumed whatever nitrate was present in the water and then died off. The smell will be... tremedous :o
If (big if) you plan on hooking it back up - you'll want to flush it out with fresh water for at least 4-5 days first. Fill a bucket with fresh water and hook up a pump to cycle the water into the unit and then back to the bucket. Change this water frequently. Keep flushing it until there is no more smell. Then re-flush it for a day or two with salt water. Once you re-hook it up to your tank/sump - it will re-cycle.
Z
Interesting...wait...what... oh s**t, I gotta go...
:)... ???...:o...:(...:'(......:P ::) ;)