Carbon source for macroalgae instead of CO2....?

[redfishsc]

If we are wanting to proliferate the growth of macroalgae in refugia, it seems as if some source of carbon would help them grow and metabolize nitrates and phosphates.


From my years of keeping planted tanks, I know just how much a strong carbon source can energize the plants.


But we can't dose CO2 into a reef tank for pH reasons (well, I assume, anyway).


Are there any alternative sources for carbon? I don't know if the carbon some folks dose (ie, vodka, glucose, vinegar) is useful for macroalgae.

[HighlandReefer]

If you were going to be putting seagrasses into a refugium or Display Tank, perhaps CO2 may be needed to help lower your pH and increase seagrass growth. Seagrass is a true vascular plant with true roots.

For macroalgae, I would suggest to try dosing iron, which will increase the growth of macro IME.

[redfishsc]

Yup, been dosing the fergon recipe and it does make a difference.

I've simply been wondering if CO2 availability (or carbon in general) might be a limiting factor in a reef tank.

[HighlandReefer]

I don't believe CO2 is a limiting factor in reef tanks, especially for macro. If anything, many hobbyists have too much CO2 in their system from the surround house air.

I have read that CO2 can become a limiting factor when raising seagrass. Many seagrass hobbyists experience to high a pH level, due to the amount of CO2 they can they take up. In this situation, introducing CO2 in a tank may be called for.

[redfishsc]

Interesting. I wouldn't have guessed that about seagrasses. I'd have a hard time growing them in my small tanks ;)


What's nagging me is that I have a complete CO2 system from my freshwater days sitting unused. When I sold all my tanks in a prior move, I kept the CO2 stuff, including the aluminum 20# canister. I'm sure one day, when the need arises, it will become a calcium reactor.