Sulfur media

[ganjero]

Does anyone know an alternative to the sulfur media sold for aquariums? Aquarium media seems hard to find and expensive. Does the media need to be in sphere shape?

 

[bertoni]

The media doesn't need to be spherical, just pure enough and with a good amount of surface area. I don't know of any alternatives off-hand, but there are denitrator designs that don't use sulfur at all, if you're interested in saving some money.

 

[Dr. Reef]

BRS has sulfur in stock made by skimz.

https://www.bulkreefsupply.com/1500...MIy9m6-5-L5AIVexitBh1aMQN8EAQYASABEgLlJvD_BwE

And you can also use soil sulfur which is 99% pure.

https://www.zenhydro.com/soil-sulfu...MIy9m6-5-L5AIVexitBh1aMQN8EAQYEiABEgK18PD_BwE

 

[ganjero]

Thank you both

 

[ganjero]

The media doesn't need to be spherical, just pure enough and with a good amount of surface area. I don't know of any alternatives off-hand, but there are denitrator designs that don't use sulfur at all, if you're interested in saving some money.

What are the other designs that don't use sulfur?

 

[bertoni]

You can just a coil denitrator, for example, that has no media, just an anaerobic zone. The denitrifying microbes can grow in anoxic regions and process nitrate without sulfur. I don't know that it's clear how much the media in a sulfur reactor actually matters other than as surface area. That's be an interesting experiment, although I don't know how to run it.

 

[Dr. Reef]

Here is the science behind the sulfur denitrator:

Sulfur denitrification is a form of chemotrophic denitrification typically done by a bacterium called Thiobacillus denitricans
It can only be done in an anaerobic environment (not anoxic)

Sulfur (usually in the form of granules not powder) is consumed and so has to be periodically replaced.

Here is the formula -

11S + 10NO3 + 4.1HCO3 + 0.5CO2 + 1.71NH4+ + 2.5H2O. -----> 0.92C5H7NO2 (biomass) + 11SO42- + 5.4N2 + 9.62H+


Basically, the bacteria combine sulfur, nitrate and carbon plus a little ammonium and form cell biomass, sulfate, nitrogen gas and acid.

The water exiting the sulfur reactor CANNOT flow directly back to the fish/coral tank because the pH is really low. Usually the water is passed through activated carbon and calcium carbonate before going back to the fish/coral tank.

Compared to coil denitrator there is anaerobic zones where bacteria can grow and process nitrates. Only problem with coil denitrator is the flow. It has to be slow I mean really slow but once nitrates are down to 0 then flow has to increase and that's where a balancing act comes to play. If flow is too fast you lose the cycle and if flow is too slow it produces Hydrogen sulfide gas which in numbers will kill fish over time.

I find sulfur reactors to be a bit more work with media and finding a sweet spot while coil denitrator is a bit easier to work with with little to no maintenance once you figure the right flow rate.

 

[ganjero]

Thanks again.

 

[bertoni]

It can only be done in an anaerobic environment (not anoxic)

"Anaerobic" generally refers to metabolism, not to environment in biology. The environment can be anoxic; the bacteria perform anaerobic denitrification.

Compared to coil denitrator there is anaerobic zones where bacteria can grow and process nitrates. Only problem with coil denitrator is the flow. It has to be slow I mean really slow but once nitrates are down to 0 then flow has to increase and that's where a balancing act comes to play. If flow is too fast you lose the cycle and if flow is too slow it produces Hydrogen sulfide gas which in numbers will kill fish over time.

I find sulfur reactors to be a bit more work with media and finding a sweet spot while coil denitrator is a bit easier to work with with little to no maintenance once you figure the right flow rate.

I haven't seen any data that the flow rate is easier with sulfur reactors than with coil design, but that might be true.