How to know if someone’s tank is carbon limited?

[Miami Reef]

If someone stopped all dosing of vodka and dose weekly water changes at 15%, runs activated carbon…

Will they become carbon limited? Does feeding fish food inadvertently add carbon?

The carbon I’m mainly referring to is the carbon in vodka or vinegar that increases coral polyp extension, Zooxanthellae, binding organics, and increasing organisms (like sponges).

How to know if a tank is carbon limited?

 

[Brymac1]

Curious about this as well.

 

[taricha]

I did some measurements of my fish food and found it to be ~50-55% organic carbon, if you're curious how much carbon is added by feeding. This would be less in meaty foods like straight shrimp/mussels etc.
Also the organisms we care about most are photosynthetic and produce their own carbon from light.
And frankly, they don't like it all that much if you flood the system with a bunch of organic carbon. They thrive in water with a very low dissolved organic carbon.

 

[Randy Holmes-Farley]

Depends on what you mean by carbon limited.

In a sense , all normal reef aquaria with any measurable N and P are almost certainly carbon limited in that adding easily metabolized organic carbon (such as acetate) will encourage bacterial growth.

FWIW, I do not know if soluble organic carbon induces polyp extension.

 

[Miami Reef]

Depends on what you mean by carbon limited.

In a sense , all normal reef aquaria with any measurable N and P are almost certainly carbon limited in that adding easily metabolized organic carbon (such as acetate) will encourage bacterial growth.

FWIW, I do not know if soluble organic carbon induces polyp extension.

Thank you. I want to increase sponge and bacterial growth which the latter will feed organisms in the tank, thus increasing growth rate and polyp extension.

 

[Randy Holmes-Farley]

Thank you. I want to increase sponge and bacterial growth which the latter will feed organisms in the tank, thus increasing growth rate and polyp extension.

I think it is virtually certain that adding something easily metabolized like vinegar will increase bacterial levels.

 

[Miami Reef]

@Randy Holmes-Farley

Quick question for you: why did you want to encourage sponges in your tank? Especially since they can potentially grow over and kill corals?

The reason I want them is because I have a moorish idol that could benefit from supplementation. If not for this, I’d probably stop all silica dosing unless I saw a different benefit to sponges?

I know diatoms are beneficial, but I want to know why you are such an advocate for sponges?

 

[Randy Holmes-Farley]

@Randy Holmes-Farley

Quick question for you: why did you want to encourage sponges in your tank? Especially since they can potentially grow over and kill corals?

The reason I want them is because I have a moorish idol that could benefit from supplementation. If not for this, I’d probably stop all silica dosing unless I saw a different benefit to sponges?

I know diatoms are beneficial, but I want to know why you are such an advocate for sponges?

Why grow corals and not sponges? lol

If I had one of the very few problem sponges, I might think differently, but I wanted to grow sponges, including a couple of larger ones I purchased (yellow ball sponges), just like folks want to grow corals.

They also filter the water.

 

[Miami Reef]

Let me revive this thread:

What are the ingredients to grow those natural sponges? Is this a good “shopping list”?

In addition to regular reef parameters:

Vinegar dosing
Silicates
Phytoplankton

Are these 3 things the “recipe” to grow sponges?

 

[Randy Holmes-Farley]

I do not know if those are "the" recipe, but they will help.

 

[Miami Reef]

I do not know if those are "the" recipe, but they will help.

Does higher PH effect sponge growth as well?

 

[Miami Reef]

A

I do not know if those are "the" recipe, but they will help.

Also, do you know of anything else that will encourage sponge growth?

 

[Randy Holmes-Farley]

Does higher PH effect sponge growth as well?

I do not know, but if it does, its not for the same reason. It is easier to precipitate coral calcium carbonate skeletons at higher pH.

Most sponges do not form calcium carbonate, and those that do may not be growth limited by it.