“I seldom use the term ‘revolutionary’ but I think this is a truly revolutionary method of replenishing calcium and alkalinity all at once in our reef aquarium.” – Lou Ekus on CalboCalcium at Reef A Palooza Orlando 2019.

I first heard of Calbo-Calcium from fellow youtuber and content providers Mok-yi and Ben (Inappropriate reefer, Might Nano). When they asked me how this product works and my opinion about it, I told them that I was not 100% sure about how the product works but if I had to guess, I would say that it’s some variation of Kalkwasser  (Calcium Hydroxide) (which is amazing and does work) due to its ability to raise both calcium and dKh. I told them that I would find out more, and while working the show floor of Reef A Palooza this year, I had a chance to see the manufacturers of this product so I spent some time talking with them, and I was very pleasantly surprised to find out that I was wrong. Intrigued, I sat down with the Tropic Marin team to discuss this product that I previously had no idea even existed.

Let’s get into it! What is it?

Carbo-Calcium contains organic calcium salts; Calcium Formate.

Calcium Formate is the calcium salt of formic acid. It is an odorless, white crystalline solid, and a source of Calcium and Formate ions for aqueous solutions.

On their site, it says that 1000 ml of Carbo-Calcium contains 40,000 mg calcium and 5,600 °carbonate hardness.  Which is ALOT! 

How does this product work?

• Every day, a few ml of highly concentrated solution are enough to cover the entire calcium and carbonate hardness needs.
•  Suitable for all aquarium sizes.
•  No formation of by-products (e.g. sodium chloride); the salinity and the ion balance are not altered.
•  No formation of excess carbon dioxide.
•  Suitable for an aquarium stocked with soft corals, LPS, SPS, and/or other filter feeders.
•  Easy to apply – suitable both for manual dosing and for dosing pumps.

So, no more calcium reactor or dosing 2 part?
And only few ml is enough cover the needs of the calcium and alkalinity of our reef tank?

To verify this, I reached out to a very well respected chemist friend, Dr. Craig Bingman, who’s been heavily involved in our industry, publishing many valuable science articles (click for citations on all of his work) for our hobby (MACNA and other conference speaker , you can see our interview with him here as well ) for quiet some time. This is what he told me:

Is Calcium formate a viable option to supplement aquarium for calcium and alkalinity?

“Calcium formate is somewhat like calcium acetate. Both are calcium salts of organic acids, and both acetate and formate need to be oxidized to bicarbonate before they will support calcification.”

What are some negative aspect(s) of this method? (all products have cons right?)

“Formic acid is oxidized to carbon dioxide and half a water molecule.”  What this means is that, like the manufacturer stated, “I suspect that oxidation is mainly carried out by bacteria. A number of groups of bacteria can carry out that reaction.”

While getting into that, I found out something interesting. Possible additional benefit?

“If most of the alkalinity is coming into the system as formate ions, formate will become one of the major carbon sources for the aquarium. I’m not sure what effect that will have on the abundances of various types of bacteria in the system. Certainly formate can be used to reduce nitrate, so some good things might happen.”

Calcium, alkalinity, and potential carbon dosing all in one? This isn’t even listed in the product description and it had me so fascinated with the idea and the concept of it.

After speaking with Dr. Bingman, I am convinced that it CAN work for most tanks BUT I would contact the manufacturer first before testing it out on fully stocked SPS tanks that demand tons of calcium and alkalinity, as it can place a burden on the animals while formate is being transformed to bicarbonate. As with any type of dosing, please make sure that it will fall within the guidelines of manufacturer’s recommendation of proper dosage. Contacting the manufacturer for consult is always recommended before making any changes like this and I strongly urge you to do so. It is my hope to one day have someone like Dr. Bingman to their booth so I can geek out and learn everything about this. I know I will be back to their booth at RAP NY to find out much as I can about it.

Proper Dosage:

Tropic Marin’s website had a dosing calculator that I can use to utilize how much product is needed to keep my aquarium in the level that I want it to be and how long it will last. (Here is the link to the product info, recommended dosages, and dosing calculator)

This is a good, viable solution for supplementing calcium and alkalinity in your aquarium. As with any trace supplementation, PLEASE take caution, read and follow the directions precisely for a thriving, successful experience with this product! Hope this was helpful.

Happy reefing!