I'm old-school: I operate without a doser. How?


Staff member
RC Mod
Without a doser and without a calcium reactor....(the latter is ok if you're 70 gallons of wildly growing coral. If a little less wild, you can use this up to 100 gallons, but if your corals really take of, time to consider a reactor.

What needs calcium dosing? stony coral (lps or sps) or clams. Other critters can get by on what comes in your salt mix.

How do you know you need this?
Stony coral can go to sleep when conditions aren't right. It shuts down and doesn't eat. How hungry are they when they do eat? I had a 3-head euphyllia, a pocillopoa, and a bubble coral in a 50 gallon tank. I was dosing by hand, a teaspoon here, a teaspoon there. Then they started to eat. 2 tsp. 4. 8...needing more. (How did I know that? Water wouoldn't stay balanced. The coral was yanking the calcum out of the water.) ---And powdered calcium is PRIcey. 'Dripping kalk' was my way to stop bleeding money.

So how does this work?
You need a stable water balance to start with: salinity 1.024, calcium 420, alkalinity dkh 8.3 (my preference), and magnesium aboiut 1350 (must not fall below 1200). If you start addig calcium, this ratio will 'lock' and stay stable until the magnesium falls below 1200. Then thnigs will start going 'off.' So test these three once a week, particularly mg, and you're good so long as the calcium holds out.
To supply calcium, I dump about 2 lbs of Mrs Wages Pickling Lime (calcium) into my 32 gallon ro/di reservoir. And stir. A lot of it will sink to the bottom as a white gunk. OK. That's because only 2 tsp per gallon will dissolve in fresh water at normal ph. As the ro/di refills with more ro/di, the excess kalk will go ahead and dissolve. So this tank with its residue on the bottom is good for several months. It's that easy. Long as you keep dumping more ro/di in, kalk keeps dissolving into it and your corals eat---cheaply.
Are there impurities in Mrs Wages? Yep, but harmless ones. Once a year, hose the barrel out and start over.

"But I don't have room for a 32 gallon reservoir!" ---Sure. No problem. A bucket will do. Just figure gallons, add teaspoons within reason, and just keep adding ro/di as needed.

If you have to leave your tank for a week, heck, just put your topoff unit in a BIG reservoir, say a Brute trashcan sitting next to your tank, and you are good to go. I have once had have my tanksitter top off the 32 gallon tank, but thanks to the Mrs Wages in the bottom, which obligingly dissolved into the new fresh water, it stayed in balance, and I got home to happy corals.


New member
I used to put kalk in a 1 gallon water jug and use airline to make a slow drip into the sump. Covered the evap for the day and the calc needs.


So for us starting out with some softies and anemones, we don't need to worry about this at all, correct?


Reef gardener
Kalkwasser is the only way I'll run a reef. Everything I did in terms of maintenance/dosing/testing frequency changed almost overnight once I started using it....plus my corals told me they were happy through their growth and appearance. It's so simple and really just makes life easier.

My DKH never drops below 9.8 and my Ca stays around 440-450....and the Kalkwasser does all the work. However, my tank really drinks up the available Magnesium, so I have to dose BRS Magnesium Mix weekly with my water change. I can live with that....

IMHO it's the only way for most reefers to really keep PH stable in the mid 8's. As mentioned by the OP, just make sure that your parameters are in range right when you start using it


Staff member
RC Mod
Those of you with softies, you're generally ok because your critters won't gulp calcium the way stony does. HOWEVER, hitting this water balance is good for them because it keeps the water ocean-like and buffered so the readings stay stable for long periods. Corals in general like stability. Your softies won't use the calcium, but they will like the steady conditions.