Thoughts on Sulfur Reactor

[JJP9398]

I built a sulfur reactor and wanted to test it out before putting it on my display tank. I'm running it on a five gallon bucket of old high nitrate tank water. When I started the test the nitrate level in the water was 52.7. After 24 hours (Monday) the level coming out of the reactor was 46.2 but now on Wednesday I have 75. Do you think it will work? Should I let it ride? Or, do you think it has to be "live" tank water for it to work? Thanks in advance.

 

[Cousteau666]

"Let it ride," it's only been a couple of days. You are relying on autotrophic bacteria to remove nitrogen waste. The bacterial colonies responsible will simply take time to mature. Your difference in results sound like errors in testing. What brand of test do you use?

Also, would you mind sharing a picture of what you built?

 

[JJP9398]

I'm using Hanna nitrate HR. I also use Salfert just to use as a gauge to save on reagents.
Here is a pic of what I built.

 

[Cousteau666]

Both decent brands. Still though, the results seems inexplicable given this set-up in your picture. I would maybe keep an eye on your sampling technique.

That build looks good! Nice!

Just to double check: the flow is coming in through the bottom of the reactor, correct?

Also, can you help me determine the height and diameter of the pipe you built the reactor with?

 

[JJP9398]

Yes, the flow comes in from the bottom. I have the dry circulation pump sucking from the top and going into the bottom of the reactor. Also there is a small return pump in the bucket that is pushing the "tank" water into the bottom also. The effluent comes out the top and then back into the bucket.

As for the size of it, I used 3 inch clear pvc. It's is 17.5 inches tall. My display tank is about 120 gallons. According to Parkers Reef on youtube I have 3 cups of sulfur and a little over 1 cup of ARM.

 

[Cousteau666]

Yes, the flow comes in from the bottom. I have the dry circulation pump sucking from the top and going into the bottom of the reactor. Also there is a small return pump in the bucket that is pushing the "tank" water into the bottom also. The effluent comes out the top and then back into the bucket.

As for the size of it, I used 3 inch clear pvc. It's is 17.5 inches tall. My display tank is about 120 gallons. According to Parkers Reef on youtube I have 3 cups of sulfur and a little over 1 cup of ARM.

I would add a valve on the incoming line then, to help throttle flow, instead of, or in addition to the valve up top, and test for nitrite. As the reaction becomes detectable it will first begin producing No2.

Additionally, and take this as you will, with nitrates values below 50mg/L the recommended volume of sulfur media is 1% of your tanks volume.

With Nitrate values above 50 mg/L the recommended volume of sulfur media is 2% of your tanks volume.

As for your sulfur media, you likely do not have enough; see, at 120g of H20, and being that there is 7.48g of water per ft3, we can do the meath and show this leaves you with a volume of ~16 ft3. Again, the recommended media ratio being 100:1 or 1% of the tanks volume would work out to be 0.16 ft3 of sulfur media. Since each ft3 has 119 cups per ft3, the math then works out to be 19 cups of media. you have three?

Determining Media Needs:​

1.) Convert gallons to cubic feet:
120g / 7.48 (g/ft3) = 16.04 ft3

2.) Take 1% of your tank v in cubic feet (ft3):
16.04 ft3 * .01 = 0.1604 ft3

3.) Convert cubic feet to cups:
0.1604 ft3 * 119.68(cups/ ft3) = 19.19 cups

The source water's nitrate values running above 50 mg/L would mean you specifically need 2% of your tanks volume, which would put you at 38 cups of media instead (That is a lot.) Implying you were using an imperial cup which would hold ~285 mL.

My advice, if you would like to hear it -I would ditch the calcium and fill it's space with more sulfur and additionally I would recommend building a second tube with straight sulfur and run them jointly and in series. This would also mean lowering No3 to less than 50mg/L to be successful, and using slooooow flowrates.

Instead of calcium you can aerate the effluent to off gas the Co2 produced by the reaction and this will help with preventing changes in pH.

As you can see from the picture, these things have a tendency to get gigantic in order to function properly.

 

[JJP9398]

Ok, that's a lot to unpack, I used this web site to figure out how much media to use. https://reefkeeping.com/issues/2009-01/diy/index.php

His equation is:

To determine how much sulfur media you need, you should multiply your total system gallons x .006. For example:

120 gallon system x .006 = .72 liters of media or about ¾ of a liter.
That's where I got the 3 cups.

I understand what your saying is 1% of 120 gallons is 1.2 gallons convert that over to cups would be around 19 cups of sulfur. Would there be any harm if I go to much on the sulfur? If not I will build a second tank and put more sulfur in there. I've read that there can be a rotten egg smell but I would just have to increase the flow into the reactor.

My display tank usually hovers around 50ppm on nitrates so I could do a large water change to bring that down.
The end goal for this is to cut down or eliminate water changes. Right now I do a 20% water change weekly.

Thanks for your help.

 

[Cousteau666]

Ok, that's a lot to unpack, I used this web site to figure out how much media to use. https://reefkeeping.com/issues/2009-01/diy/index.php

His equation is:

To determine how much sulfur media you need, you should multiply your total system gallons x .006. For example:

120 gallon system x .006 = .72 liters of media or about ¾ of a liter.
That's where I got the 3 cups.

I understand what your saying is 1% of 120 gallons is 1.2 gallons convert that over to cups would be around 19 cups of sulfur. Would there be any harm if I go to much on the sulfur? If not I will build a second tank and put more sulfur in there. I've read that there can be a rotten egg smell but I would just have to increase the flow into the reactor.

My display tank usually hovers around 50ppm on nitrates so I could do a large water change to bring that down.
The end goal for this is to cut down or eliminate water changes. Right now I do a 20% water change weekly.

Thanks for your help.

Haha somewhat, yeah.

Too much sulfur? I am not sure. If you prefer a conservative approach, you can start by running straight sulfur in the one you have now, and monitor for the rotten egg smell. If it does not seed, then you can just build the second and tune it in.

 

[ca1ore]

I ran a large sulfur reactor on my previous 450. It was an aquarium engineering (company now defunct) model with sizable capacity. I’d estimate I probably had close to 2 gallons of the sulfur media, with coral rubble on top. Did a fantastic job of reducing nitrates, but I also got elevating levels of sulfates (it’s been a while, I think it was sulfates). It was around that time that I started to have unexpected challenges keeping SPS - could have been correlation rather than causation, but the timing was suspicious.

 

[JJP9398]

After doing some more research and with the help from here I'm working on version 2 of this reactor. In the works is a 6x24" pvc pipe. This one will easily hold more than 20 lbs of sulfur plus the ARM. I plan on having a probe holder so I can monitor ORP.

 

[FinalPhaze987]

I ran a Midwest sulfur denitrator years back...kept levels undetectable, but corals were very pale...tuning it was always the hard part as it was all counting drops per minute..the sulfur media starts to crumble after a while as well, so mind your flow rate