Selecting an export method: carbon dosing vs macro growubf

[Reefer Dan]

I have finally hit that balance on the scale between input and output, meaning I’m not having to dose and my nitrate/phosphate levels are fairly stable with feeding and fish; however, I still have a few more fish that I’m planning to stock and know that this will tilt the balance towards the need for greater nutrient export and would love to have a plan.

I have been going back and forth between these two options and have been reading a lot on them, but haven’t been able to come to a clear conclusion:
1) reverse schedule macro growing (“refugium”) with like chaeto, etc.
2) trying carbon dosing (vinegar).

I have been fighting some problem algae, but the biggest thing I’ve been fighting is cyano… I have mostly taken care of the red, but the green has been starting to be more rampant. I’ve been leaning toward the macro route since carbon dosing can make cyano worse.

Open to insights and thoughts on this! Also side note, I haven’t seen any guides on how to select which one is right for you, just ones on how to do each method—it would be extremely helpful if you could also post your reasoning on insights and thoughts for myself and future people.

Tank (75g +20g sump) :
Established 1.3 years
Parameters:
temp 76-77F/salinity 35 ppt
Ca: 425 ppm
Alk: 8.8 dkh
Nitrate: 8.5 ppm
Phosphate 0.06-0.08 ppm
Filtration: basic- filter floss changed daily, activated carbon changed every 3ish weeks, protein skimmer.

Pics of my tank (+ cyano problem):

 

[Randy Holmes-Farley Verified Community Expert]

All methods have pros and cons. If I had to choose one I'd use macroalgae. I used both in my system, along with other methods.

Carbon dosing can be imbalanced to more nitrate removal and less phosphate due to the process of denitrification that reduces nitrate and not phosphate.

Macroalgae may use more trace elements such as iron and manganese, but also helps boost O2 and pH.

 

[Subsea]

I suggest you add biofloc to encourage targeted bacteria to outcompete algae and in turn to be exported by your protein skimmer.

 

[Reefer Dan]

All methods have pros and cons. If I had to choose one I'd use macroalgae. I used both in my system, along with other methods.

Carbon dosing can be imbalanced to more nitrate removal and less phosphate due to the process of denitrification that reduces nitrate and not phosphate.

Macroalgae may use more trace elements such as iron and manganese, but also helps boost O2 and pH.

Thank you Randy. I was leaning towards this option also. I love your insights. It seems more simple to me and that is what I am for. I dose less than recommended TM elements k/a, so I should be able to bump this dosage up and handle that, right? Or would it be recommended to have a separate one like chaetogro?

 

[Randy Holmes-Farley Verified Community Expert]

Thank you Randy. I was leaning towards this option also. I love your insights. It seems more simple to me and that is what I am for. I dose less than recommended TM elements k/a, so I should be able to bump this dosage up and handle that, right? Or would it be recommended to have a separate one like chaetogro?

Thanks. I don't know which would be a better product to use, and it may not matter, but I have more confidence in the formulation capability of Tropic Marin than I do of Brightwell, and would personally pick the A and K, and dose higher if needed.

 

[Lavey29]

Thank you Randy. I was leaning towards this option also. I love your insights. It seems more simple to me and that is what I am for. I dose less than recommended TM elements k/a, so I should be able to bump this dosage up and handle that, right? Or would it be recommended to have a separate one like chaetogro?

Weekly water changes suffice to replenish trace elements. If you go longer between water changes then a supplement such as chaeto gro may be needed for your macro.

 

[Randy Holmes-Farley Verified Community Expert]

Weekly water changes suffice to replenish trace elements. If you go longer between water changes then a supplement such as chaeto gro may be needed for your macro.

How do you know that?

While one can debate what levels of trace elements are actually needed, I did not maintain detectable levels of iron or manganese or vanadium (and more) by ICP even when doing significant water changes (about 1% daily).

 

[Lavey29]

How do you know that?

While one can debate what levels of trace elements are actually needed, I did not maintain detectable levels of iron or manganese or vanadium (and more) by ICP even when doing significant water changes (about 1% daily).

Well, my ICP tests when I was doing weekly water changes showed adequate levels of trace for my tank and fuge. Now I'm doing water changes every 3 or 4 weeks and ICP showed trace deficiency in certain areas such as iodine and Manganese hence the need for trace dosing between water changes.

 

[Lavey29]

How do you know that?

While one can debate what levels of trace elements are actually needed, I did not maintain detectable levels of iron or manganese or vanadium (and more) by ICP even when doing significant water changes (about 1% daily).

And I should add that the trace levels that were below standard were only down small amounts but enough that I wanted to dose supplement just to keep everything balanced in the good range. I use red sea ABCD trace now but did use Chaeto gro effectively to prior to that.