Are nutrients truly zero? Is this really a problem?

[arking_mark]

My nutrients and alk started to creep up beyond my target ranges which I attributed to a maturing tank (1 year old).

NO3 which was typically 6-12ppm went up to 16, PO4 which was typically 0.06 - 0.1 went up to 0.13, and reducing input was not having an impact.

So, I figured it was time to carbon dose and proceeded to make DIY NoPox.

I started with 1/4 the recommended dose for my tank (4ml for a 400L).

Within 6 days my nutrients went back into target range, and I reduced the DIY NoPox dosing to 2ml per day.

5 days later, I hit zeros for PO4 and NO3 and reduce the dosing to 1ml per day and increase input (food).

But my question is, do I truly have zero PO4/NO3? Or is it just being taken up and made available to my coral via bacteria?

 

[blaxsun]

Or your testing kit could be off. What are you using?

 

[arking_mark]

Or your testing kit could be off. What are you using?

Hanna Marine Master Multiparameter Photometer.

 

[J1a]

N and P elements exist in the aquarium in many forms. Zero readings on nitrate and phosphate tests does not mean there are no nutrients in the aquarium.

Some maybe bound in planktons which coral can prey on, some may exist in organic forms (amino acids, organic phosphates) which cannot be tested by the kits.

There is also a problem of limit of detection on those tests kits. If the level is lower than the LoD, it will be reported as zero while in fact it's just very low.

 

[Pico bam]

N and P elements exist in the aquarium in many forms. Zero readings on nitrate and phosphate tests does not mean there are no nutrients in the aquarium.

Some maybe bound in planktons which coral can prey on, some may exist in organic forms (amino acids, organic phosphates) which cannot be tested by the kits.

There is also a problem of limit of detection on those tests kits. If the level is lower than the LoD, it will be reported as zero while in fact it's just very low.

Well said and good information.

 

[Randy Holmes-Farley]

But my question is, do I truly have zero PO4/NO3? Or is it just being taken up and made available to my coral via bacteria?

I don't know if it is available to corals or not, but it is undesirable to be undetectable.

FWIW, it is never truly zero, but certainly can be below kit detectable.

 

[arking_mark]

I don't know if it is available to corals or not, but it is undesirable to be undetectable.

FWIW, it is never truly zero, but certainly can be below kit detectable.

Well, I guess the question is whether I should stop the NoPox dosing which is at 1ml per day or just increase feeding. My recollection was that carbon dosing has other benefits for the tank...thoughts?

 

[arking_mark]

BTW, I never thought carbon dosing would be this effective or work this quickly.

 

[Randy Holmes-Farley]

Well, I guess the question is whether I should stop the NoPox dosing which is at 1ml per day or just increase feeding. My recollection was that carbon dosing has other benefits for the tank...thoughts?

Personally, I'd keep dosing organic carbon (any type, primarily to provide bacteria for filter feeders) and then either feed more or dose N and P.

 

[Randy Holmes-Farley]

BTW, I never thought carbon dosing would be this effective or work this quickly.

It often doesn't, and might be test variability. lol

 

[J1a]

Well, I guess the question is whether I should stop the NoPox dosing which is at 1ml per day or just increase feeding. My recollection was that carbon dosing has other benefits for the tank...thoughts?

I feel carbon dosing is a rather "harsh" method. It does reduce nitrate and phosphates rapidly. However, it can potentially alter the composition of bacteria in the system, or lead to more oxygen consumption.

Maybe it's just me, but I feel increase feeding so that we can carbon dose to remove the excess nutrients to be kind of taking the detour. If bacteria is what we want to provide to the filter feeders, why don't we add them straightaway.

 

[Pico bam]

I'm in the same boat as you, I bought 5liters of nopox figuring I would save money in the long run. Started at a quarter of the recommend dose I had a bacterial bloom, witch had me a little worried. Bacterial blooms have shut down two of my tanks in the past. But this time it just came and went. I was also using phosphate E from brightwell's for phosphates reduction. Long story short im dosing .1 ml of nopox a day and have undetectable phosphate. Still have 4975 ml of nopox lol this is going to last a long time at this rate.

 

[arking_mark]

Personally, I'd keep dosing organic carbon (any type, primarily to provide bacteria for filter feeders) and then either feed more or dose N and P.

Great, I'll try that.

Increasing dry feeding by 30% (Plank feeder) and upping the daily frozen to twice a day,

 

[arking_mark]

I'm in the same boat as you, I bought 5liters of nopox figuring I would save money in the long run. Started at a quarter of the recommend dose I had a bacterial bloom, witch had me a little worried. Bacterial blooms have shut down two of my tanks in the past. But this time it just came and went. I was also using phosphate E from brightwell's for phosphates reduction. Long story short im dosing .1 ml of nopox a day and have undetectable phosphate. Still have 4975 ml of nopox lol this is going to last a long time at this rate.

The DIY NoPox was so easy and cheap...highly recommended.

 

[arking_mark]

I feel carbon dosing is a rather "harsh" method. It does reduce nitrate and phosphates rapidly. However, it can potentially alter the composition of bacteria in the system, or lead to more oxygen consumption.

Maybe it's just me, but I feel increase feeding so that we can carbon dose to remove the excess nutrients to be kind of taking the detour. If bacteria is what we want to provide to the filter feeders, why don't we add them straightaway.

Curious. Are you recommending dosing something like Microbacter 7?

 

[X-37B]

Carbon dosing has a benifit and I started dosing again after 4-5 months off.
I only dose a small amount and do not use it for no3 or po4 reduction.
I had a similar no3 issue going from <5 to 20. I upgraded my skimmer and no3 runs<5 now.
I was running gfo and phosgaurd mixed to keep po4 at <0.1.
I setup a remote 30g fuge to reduce/eliminate po4 reducing agents. 6 weeks in and my po4 reducing agents are at 50% less and counting.
I used to change media every 3-4 days and just changed it at 2+ weeks when po4 got to .08 so the fuge is working.

I also feed my 15 fish only and heavy at 8+ cubes a day.

 

[J1a]

Curious. Are you recommending dosing something like Microbacter 7?

No. I don't think the bacteria density in mb7 is meaningful as food.

I use freeze dried bacteria, phyto- and zooplanktons to directly supply food to my corals.

 

[Lavey29]

Even though your numbers went up slightly as you indicated your tank matures they were not high at all. Why even put more chemicals in to lower them? Was your tank showing negative reactions? Seems like it is easily managed with proper feeding and water change? Maybe more wet skim? Just don't see the point of always reacting with chemicals dosing.

 

[X-37B]

No. I don't think the bacteria density in mb7 is meaningful as food.

I use freeze dried bacteria, phyto- and zooplanktons to directly supply food to my corals.

I do not feed my corals, altgough many do.
A small amount of carbon dosing is better than coral foods, imo.
Also feeding your fish more, as long as you have the nutrient control, is a better optuon, imo.

 

[J1a]

I do not feed my corals, altgough many do.
A small amount of carbon dosing is better than coral foods, imo.
Also feeding your fish more, as long as you have the nutrient control, is a better optuon, imo.

Yeah. This is also one way to run the aquarium.