I employed carbon dosing (vinegar) for some time in the past . My experience seems to fall in line with a lot of the “newer” thinking that’s become prevalent in last several years, but that’s my subjective take on it , so take my words with a grain of salt.
Past goal- management nutrients with moderate carbon dosing in hopes of achieving a good looking and healthy tank, while minimizing reliance on GFO and other additional nutrient reduction efforts.
Past outcome- tank seemed good. Ongoing battles with limited nuisance algaes, never completely overwhelmed but never free of nuisance growth. Good coral growth, colors looking a bit “pastel” consistent other tanks of that time employing carbon dosing and the ULNS thinking. Essentially things were manageable, and nitrate / phosphate would test at low or undetectable levels - yet I was still always dealing with nuisance algae and had to be quite sparse about feeding to stay more or less in balance.
Skip ahead a marriage, loss of interest in the hobby, pandemic and 5 years of ignoring my tank. Then found new motivation at the start of this year.
> cleaned up tank, started planning for a new plan. Here I am;
Now - no carbon dosing. I’m feeding 3x as much (at least) than in the past. Tank looks cleaner, and I’m seeing improved growth compared to anything I’ve seen in the past.
What’s different? No carbon dosing, daily fresh phyto, more aggressively feeding.
What’s happening? I think this is a much better cycling of nutrients. Fresh food goes in, gets eaten, then waste broken down more effectively and thoroughly leaving little inorganic waste to fuel problems (or to rely on carbon dosing to then remove). Phyto seems to help by absorbing available nutrients AND then getting consumed, feeding said nutrients back to corals and other desirable life instead of feeding nuisance growth.
One way or another I’m doing much better at managing nutrients and keeping a healthy tank by using different strategies other than carbon dosing.
Can carbon dosing be a useful in managing nutrients? Absolutely yes. Will it be as effective as I had hoped in the past, the way I had hoped it would? Nope.
What (I think) I’ve learned? Carbon dosing is great for removing the end result, ashes if you will, left over from inefficient metabolism.
AND
Our tanks (ok at least mine) are like living things themselves, with energy input, output, and metabolism. The athlete eats a lot of healthy foods and rapidly metabolizes them leading to great, relatively efficient, outputs (muscle growth and output - coral growth) and nearly zero accumulating belly fat (nuisance growth).
Nuisance algae is like belly fat. We all consume 1000s of calories daily, and we all burn a lot. A few too many calories, and not quite enough burning of said calories, and we have an excess around the margins which becomes belly fat (or nuisance growth).
Get a system metabolizing like a marathon runner, and it may get hard to grow nuisance algae. Get a system metabolizing like a “video gamer”. (No offense intended to anyone) sitting around eating fast food, then belly fat and or nuisance growth become almost a given.
My take away - I’d use carbon dosing again to deal with accumulated ashes (I believe Dong gets the credit for that analogy) in the form of accumulating nitrates and phosphates. I wouldn’t rely on carbon dosing to manage those nutrients in the first place.
Practically for the questions about how to use carbon dosing- I’d say there are only very vague guidelines. You really have to start modestly, watch and monitor closely and adjust/ increase accordingly. Every tank is different.
