Anyone using organic calcium?

[cherubfish pair]

Calcium EDTA or Calcium gluconate? I know they polute the water, but what if you just used to target feed 3 or 4 corals?

[bertoni]

SeaChem makes a supplement of calcium bound to polygluconate. It seems to add both calcium and alkalinity, and can cause cyanobacteria issues. Calcium acetate is also used as a one-part supplement, but is fairly expensive.

I don't know of any way to target feed calcium to corals, though. I'm not sure what that would accomplish.

[tmz]

I agree. It seems to me attempts to target feed could be harmful due to localized concentrations. As I understand it corals absorb calcium carbonate and need an environment with accepatable levels around the clock.

[jdieck]

You could use it as calcium and alkalinity supplement. As the bacteria proces the gluconate it will turn it inot carbonates while the calcium gets liverated, note that as food to bacteria if added in high amounts as Bertoni mentions it may create some bacterial blooms if added in large quantities so it is more recommended for maintenance of the levels (replace consumption) rather than making single time parameter adjustments were larger quantities may be needed.

[Randy Holmes-Farley]

I would not recommend calcium EDTA. I do not think corals will be able to get the calcium until the EDTA breaks down, such as in in UV or ozone.

I also do not recommend the calcium polygluconate. It adds an unknown amount of alkalinity as well as calcium.

Calcium gluconate (not polygluconate) will be a balanced calcium and alkalinity supplement, like calcium acetate, but drives bacterial growth, as mentioned above.

Corals do not benefit from chelated calcium. They take up unbound (ionic) calcium.

[mcneilwh]

If you go with the vinegar and lime water or other organic calcium just remember start slow. EXTRA FOOD + HIGH NUTRIENTS = ALGEA BLOOM. The nutrient levels must drop to very low levels before you will be able to dose enough organic calcium to maintain your calcium and alkalinity without getting the blooms.

I use Ca Acetate all the time. Everyone cringes when I respond to with my method, but it works great and has been bullet proof for me. I add vinegar to my makeup water (7Gal) via a dosing pump which is added to another bucket stirring (5Gal) of lime water which is feed into the sump by gravity. All is controlled by a Neptune aqua controller. After about 2 weeks the system balances out, with a steady supply of calcium, alkalinity, low phosphates without GFO, natural food for the corals, and a rock solid pH. When the alkalinity begins to drop I just add more lime to the stirring bucket, and refill the top-off bucket with more water and vinegar when empty. I also add CO2 via the Protein skimmer to compensate for the CO2 consumed by the limewater and maintain the pH during the limewater additions to the tank. Without the added CO2 limewater alone cannot keep up with the alkalinity.

I recently removed the vinegar component from my system, and my Phosphates rose from not detectable to almost 0.1 ppm, and my corals show less polyp extension and looked less happy. I had a thriving Gonipora Ultra, and a Gonipora Flowerpot. After removing the vinegar both started to RTN and are now half dead, and will probably die. This might mean that there is an addiction factor for the acetate, making acetate junkies.

I use about 1 cup of distilled vinegar for 7 gallons makeup water that is consumed over 5 days for 75 Gallons. I have pushed the limit up to 2 cups for the same time period, but I found myself using the turkey baster to remove films off the Gorgonias.

[cherubfish pair]

Originally posted by bertoni
I don't know of any way to target feed calcium to corals, though. I'm not sure what that would accomplish.

Turkey baster.

[bertoni]

I don't think that'll work, since corals are absorbing dissolved calcium.