Are biopelllets self regulating?

[jasonrusso]

On my 210 I was running 2 BRS bio pellet reactors. I always had nitrate issues because of my messy fish (mainly my porcupine puffer who likes to chew his food and spit out little bits). The reactors did a good job at keeping the nitrates low (under 10).

Recently I had to go fallow for 72 days. During this time, I swapped one reactor out and built a algae reactor out of a Phosban 550. Everything is going well, but I don't see the biopelllets being consumed as fast or at all. Is this because the nutrients are so low there is a lower concentration of bacteria to feed on the biopelllets?

As the title says, are these self regulating as the bacteria concentration rises and falls?

 

[Irsug1]

I think because you are going fallow, there are not enough nutrients for the bio pellets to consume at a similar rate as previous. I wouldn't call them self regulating, though.

 

[jasonrusso]

I think because you are going fallow, there are not enough nutrients for the bio pellets to consume at a similar rate as previous. I wouldn't call them self regulating, though.

Not fallow anymore, but nutrients are still low. I'm not going to change anything right now because things are working out well.

 

[Randy Holmes-Farley]

On my 210 I was running 2 BRS bio pellet reactors. I always had nitrate issues because of my messy fish (mainly my porcupine puffer who likes to chew his food and spit out little bits). The reactors did a good job at keeping the nitrates low (under 10).

Just a comment on that which many people misunderstand. The N and P in foods ends up in the water as nitrate and phosphate almost independently of whether it is eaten by a fish or not. They (especially adult fish) retain little to none of the N and P in the foods.

 

[Randy Holmes-Farley]

The bacteria may well become limited in their growth by low nutrients (N or P or others, such as trace metals) in a tank that isn't being fed. In the extreme case they cannot grow on biopellets alone.

 

[mcarroll]

The N and P in foods ends up in the water as nitrate and phosphate almost independently of whether it is eaten by a fish or not. They (especially adult fish) retain little to none of the N and P in the foods.

+1 because once they're grown they (like us) mostly eat for energy.

@jasonrusso This is not usually a direct link: e.g. Food>Fish>Nitrates.

Rather, there's a microbial loop that gets involved beginning inside the fish's gut and which includes all algae and other related known and unknown micro-critters in the tank – even corals, and other inverts.

This microbial loop is what we're culturing (or harming) when we allow (or zero out) nutrients in our tanks at the beginning. It's their job to cycle those nutrients in the tank and to keep them in-use.

What makes it into the water and shows up in tests is natural leakage from this loop, or when the loop is exceeded by a nutrient spike like adding a bunch of livestock at once.

Nutrients are a good thing. Leakage is not a bad thing. But nutrient spikes are to be avoided.

 

[Jon Warner]

On my 210 I was running 2 BRS bio pellet reactors. I always had nitrate issues because of my messy fish (mainly my porcupine puffer who likes to chew his food and spit out little bits). The reactors did a good job at keeping the nitrates low (under 10).

Recently I had to go fallow for 72 days. During this time, I swapped one reactor out and built a algae reactor out of a Phosban 550. Everything is going well, but I don't see the biopelllets being consumed as fast or at all. Is this because the nutrients are so low there is a lower concentration of bacteria to feed on the biopelllets?

As the title says, are these self regulating as the bacteria concentration rises and falls?

I think that's a fair characterization.

Bio-Pellets serve as a substrate and a food source for bacteria that "remove" nutrients. As nutrient levels change the density of the biofilm changes. The bacterial population indeed varies in direct proportion to the amount of nutrients in the water and the total surface area of Bio-pellets available.

Self regulation seems accurate.

 

[jasonrusso]

I think that's a fair characterization.

Bio-Pellets serve as a substrate and a food source for bacteria that "remove" nutrients. As nutrient levels change the density of the biofilm changes. The bacterial population indeed varies in direct proportion to the amount of nutrients in the water and the total surface area of Bio-pellets available.

Self regulation seems accurate.

My main point is that I see that the pellets are not being consumed as fast with the low nutrients. If the nutrients increase (and they will never be zero, which I am fine with. The ocean does not have zero nutrients) then the bacteria will increase and start consuming the pellets again.

I'm not shutting down the reactor either way. I just want to know if my theory is on track.

 

[sbazain]

when is it time to add biopellets I Hooked up my reactor 26 days ago with 1/4 of the dosing amount nitrates are still up when should I see a change

 

[mcarroll]

@sbazain Do you have any PO4 on your tests?

 

[sbazain]

yes it's at .25

 

[Randy Holmes-Farley]

when is it time to add biopellets I Hooked up my reactor 26 days ago with 1/4 of the dosing amount nitrates are still up when should I see a change

How high is nitrate?