Sulfer denitritors flow rate - math doesn't work for me

[Sierra_Bravo]

I've been reading and learning about sulfur denitrators and the one thing I can't wrap my head around is that with a flow rate of one drop per second, how can this possibly have an effect on nitrate levels?

If there are 3,785 ml to a gallon, my 120 gallon water volume contains 454,200 ml. There are approximately 20 drops to a ml, so my aquarium contains 9,084,000 drops. At a drip rate of one per second, it would take 2,523 hours or ~105 days for the entire volume of my tank to circulate through the reactor.

Given how little water circulates through the denitrator in a day, about half a gallon's worth, and the continual replenishment of nitrates through feeding and biological processes, how is the reactor consuming more nitrate than what is being introduced into the tank? Or am I missing something?

 

[SeaDweller]

I've been reading and learning about sulfur denitrators and the one thing I can't wrap my head around is that with a flow rate of one drop per second, how can this possibly have an effect on nitrate levels?

If there are 3,785 ml to a gallon, my 120 gallon water volume contains 454,200 ml. There are approximately 20 drops to a ml, so my aquarium contains 9,084,000 drops. At a drip rate of one per second, it would take 2,523 hours or ~105 days for the entire volume of my tank to circulate through the reactor.

Given how little water circulates through the denitrator in a day, about half a gallon's worth, and the continual replenishment of nitrates through feeding and biological processes, how is the reactor consuming more nitrate than what is being introduced into the tank? Or am I missing something?

Initially it IS one drop per second. Then as the population of bacteria build, you increase it. Mine is a constant stream now (after 6+ weeks of break in) and my NO3 is 0.5 ppm with 35 fish and feeding 5-6 times per day. The one drop per second phase lasts a few weeks before you up it.

 

[LobsterOfJustice]

Also, all the water doesn’t have to pass through it. Let’s say your nitrates are 50 ppm and the water coming out is 0 ppm. If 10% of the water passes through it in a week, your nitrates will drop from 50 to 45. Then the next week will drop to 40.5.

This is an overly simplified example that doesn’t include you adding more nitrate to the tank, and the fact that the reduction is constant and not batched into weeks, but the general idea is the same.

 

[ca1ore]

Do those of you running these have issues with elevated sulfate levels?

 

[SeaDweller]

Do those of you running these have issues with elevated sulfate levels?

I’ve asked this question, and no ones answered it, but Dr Reef or whatever his name is, who I think alluded to it being ok? I haven’t seen the media deplete, so who knows? Mines been up for months and no issues so far. Actually, I’ve never had bacterial mulm build up or sulfur issues building up in the reactor or gas released into my home.

 

[Randy Holmes-Farley Verified Community Expert]

I’ll answer it. Elevated sulfate is no concern. It is massively high to begin with (2700 ppm) so a small change is no concern.