Do anemones need calcium?


New member
My water parameters have been good except calcium being low. I have been adding the kent calcium buffer each day, 1 cap full. When I test it, it seems like it only goes up 1 point or zero points of calcium a day. Do I need to wait 150-200 days before adding an anemone or do they not need calcium? (tank 5 weeks old). Or how much more calcium can I add to make it go up faster, the 1 cap full per day is what it says but it doesnt really do anything.


Got Reef?
Anemones do not need calcium. Calcium is for the corals so they can grow. Nems are all soft tissue. They reason for waiting to add Nems is that they need a very stable enviroment so they dont die. Are you sure you are testing right. You should have a decent calcium level since nothing is using it. Just doing water changes usually will bring your calcium up but buffing works fine. Maybe up your dose to a cap and a half.
Alkalinity is more important to anemones than calcium, but calcium and alkalinity need to be balanced in any marine system growing inverts.
It's very important to grasp this basic understanding before attempting anything.
I strongly suggest reading Randy's reef chemistry articles in the Reef Chemistry Forum on RC.
Many commercial salt mixes are deficient in calcium and can actually bring your calcium level down.
Anemones can be tough to introduce successfully even if all levels are proper. I'd wait until everything is perfect. The extra waiting time will be good for the whole system as well as the anemone.


New member
Well, heres my water parameters so you have a better understanding.

Salinity - 1.025
ammonia - 0 ppm
nitrite - 0 ppm
nitrate - 0ppm
Alkalinity 3 mEg/l
pH - 8.4


Premium Member
I agree with Gary. All organisms need calcium to some degree or another. Chances are, anemones get most of the necessary calcium from their diet, not from the water.


New member
Oh ya, forgot to add calcium, today I got it at 285, which it stayed the same since the last time I added a cap full of the calcium buffer. So I dont know whats eating my calcium away unless its snails/crabs shells or something.


285 is very low. 8.4 dkH is also somewhat low (though in the "ok" range). Which salt are you using? How does a freshly mixed and aged batch of salt measure?


New member
t5Nitro, you are getting some very good information from some very experienced people. Keep in mind that creating a stable environment takes time.

Ancient reef saying:Only bad thing happen fast.

Anemones are not your best bet for learning reefkeeping. Start with some soft corals first. Add an anemone after you have had a year of success. It's no fun watching animals die.

Do lots of reading and enjoy.


New member
Ok, thanks for the advice, although theatrus says 8.4 pH is low? It says everywhere 8.0-8.4 usually.


New member
<a href=showthread.php?s=&postid=8111475#post8111475 target=_blank>Originally posted</a> by t5Nitro
Oh ya, forgot to add calcium, today I got it at 285, which it stayed the same since the last time I added a cap full of the calcium buffer. So I dont know whats eating my calcium away unless its snails/crabs shells or something.
Snails, any shelled animals, hichhicker corals and mainly coralline algae need calcium to grow. At that level 285 ppm you will need a lot of supplement to bring it up.
If what you are using is Kent's liquid Calcium in a 55 gal tank you will need about 56 capfulls to bring it up to 420 ppm. If you are using Kent's TurboCalcium you will need about 15 teaspoons of powder dissolved in RO/DI water.
I recommend to limit one shot increases to no more than 50 ppm per day so I would add:
a) 20 capfils of Liquid Calcium per day for three days
b) 6 teaspoons of Turbocalcium dissolved in some RO/DI water once a day for three days
and test again.

To rise your Alkalinity (I recommend 10 to 11 dKh) you can use Baking Soda dissolved in some RO /DI water at a rate of 1/2 teaspoon of powder per day for four days for a total of 4 teaspoons.

For future additions and corrections try the chemistry calculator:

Once your levels are on target you need to select a balanced method for maintaining the levels:


New member
I dont have dKh or something or other. Alk is good though according to charts, right in the middle of the level range it should be at. But 20 per day of the kent liquid? That is what I have, says one a day but can I add the 20 right into the tank just space the 20 out?
Nevermind, dkh is alk I guess, edited.
Last edited:


New member
The dose recommended in the bottle is usually meant to maintain the levels in an aquarium without much consumption, this is the reason you are not able to increase it but to keep it the same.
Kent Liquid Calcium is very safe to add. 20 caps per day is what you need for a total of 60 to increase the level. Yes it is a lot but also your Calcium is very low. After you had reached the 420 ppm level then you can go back and reduce the amount added to what is needed to maintain the level. By testing you can adjust the amount your particular tank require. If it starts dropping then just increase the daily amount and viceversa.
My preferred is the most concentrated version which is Turbocalcium. It is the same chemical (Calcium Chloride) but it is dry (concentrated) so you do not have to pay for the mixing and transportation of the water and cheaper at the end.
You will need to do something similar to maintain your Alkalinity
The reason I recommend an Alaklinity in the 10 to 11 level is that at a little higher than the middle level the calcification process is enhanced and it is easier for organisms to deposit it as carbonate thus growing faster. The second reason is that while targeting a bit higher level when adding manually basically you will have that level as your maximum so you will be fluctuating between the target and a somewhat lower level previous to the next addition.

By the way there are three units of measure for Alkalinity that you will find out there, they are dKh, Meq/lt (Milliequivalents per liter) and ppm (Parts per million)
1 meq/lt = 2.8 dkH = 50 ppm
1 dKh = 17.86 ppm = 0.36 meq/lt

The balanced ratio (as in consumption or balanced addition) of Calcium and Alkalinity is 1 meq/lt (2.8 dKh) of Alkalinity per 20 ppm of Calcium, in other words when corals or coralline algae grows it will consume Calcium and Alkalinity in that indicated ratio and this is the ratio at which two part additives add Calcium and Alkalinity.