Maintaning Ca levels with kalkwasser

[ReefDreamz]

I think I would like to begin dosing kalk in my reef. I have the tunze osmolator for top off and I would like to combine it with this tunze calcium dispenser:
http://www.tunze.com/fileadmin/gebra...x5074.8888.pdf

My reef is almost a year old now and so far I have just been doing water changes and dosing with B-Ionic to maintain my Ca and Alk. Usually twice a month (sometimes once) I will do a 20% H2O change, test Ca, Alk, and Mg, and dose B-Ionic accordingly. I cannot complain that this method has not worked. According to my maintenance log my Ca has never tested lower than 390 and always hovers around 400 (I use IO salt but recently switched to RC) which I boost with B-Ionic to 420. My alk has always tested between 3.8 and 4.2 and I have never dosed any of the alk component of the B-Ionic so alk is maintained only from water changes. All tests are Salifert.

I would like to start dosing kalk instead of the B-Ionic because although my corals are healthy they do not seem to be growing. I have zoanthid frags which have not grown at all in over 6 months as well as other LPS. Also the Ca component of my B-Ionic is gone but I do have an unopened jar of kalk.

My main questions are given my previous Ca and Alk experience: Am I a good candidate to dose kalk? Do you see any potential problems? Will the Tunze Ca dispenser work for me? How do I know how much to dose ( I cant control the rate of evaporation so I guess all I can do to control how much I dose is vary the concentration of kalk I use)?
Thanks for any information and advice.
-Cody

[bdare]

Hey Cody,

As long as your params are in check with your current dosing, I don't see why you would want to switch to Kalk. Will it save you time or money?

As for the lack of growth... are you feeding your LPS? I see you are running PC lighting. That could also be part of the reason.

[ReefDreamz]

Thanks for the response bdare. I do not "feed" my LPS or zoas directly but I do feed cyclops and mysis to the fish. I do have PC's but I have 384w of them. My params do seem to be in check but I have read that "reefs love kalkwasser" and I am hoping that using kalk will keep my params stable without me having to dose. Right now my Ca fluctuates between 390 and 420 depending on the last time I dosed.

[Sk8r]

The deal with kalk is you only have to tend to it when your topoff tank runs dry or you've used all your kalk.

I dose kalk from a garbage can of ro/di: I just dump in kalk and stir it up every time I add fresh water. Works fine...since my tank evaps 1 gallon a day. That means I can go two weeks or so without having to dose. Prior to that my tank required daily testing and daily dosing, even while using the ro/di to supply alk buffer---if I hadn't done that, I'd have been hand-dosing morning and evening to supply my corals.
You have to hand-dose to 'set' the alk and cal and mg levels, then rely on kalk to hold it there until mg runs out or kalk depletes.

Kalk works on reefs from 30g to 120g depending on density and demand of corals. Kalk works on 'voluntary' calcium uptake by ro/di water. Beyond that you may need the 'forced' calcium injection of a calcium reactor.

[Randy Holmes-Farley]

How much B-ionic are you dosing?

Do you know your daily evaporation rate?

With those values we can determine if limewater alone is adequate (it is for me, but not all tanks).

Limewater is about 68 times less potent than the original B-ionic, so see if that works out.

FWIW, limewater is all I dose for calcium and alkalinity.

[ReefDreamz]

According to my maintenance log on average I dose 7 fl oz of Ca (B-Ionic) a month. This may not be a very accurate number because I just switched from IO to RC and plan on sticking with RC. I suppose to get a very accurate # I would have to test my Ca and alk levels everyday for a month and record how much I dose. As of right now I only test and dose once or twice a month. I don't know exactly how much H20 I evaporate a day but a very rough estimate would be 0.75 gallons a day.
-Cody

[Randy Holmes-Farley]

At 3/4 gallon per day, you can dose the equivalent of a bit over 1 ounce of each part of B-ionc per day. So it should be adequate for your tank.

[ReefDreamz]

Is it ok to dose kalk directly into the display through my ATO?

[Randy Holmes-Farley]

If it is dosed to a high flow area away from corals, and the dosing is slow enough, then yes that is OK.

[ReefDreamz]

I'm still not exactly clear on how much kalk I should dose. According to the literature that comes with the tunze Ca dispenser "Reef tank with a content of less than 180 litres (48 gal. US). Add 10 g (.02 oz.) of calcium hydroxide to the calcium dispenser every ten days." Should I just go ahead and do that? I'm worried because I've never dosed a drop of the alk component of the B-Ionic and my alk stays stable with just bi-monthly water changes so if I start dosing kalk is my alk going to go up too high and drive up my pH?

[Billybeau1]

Originally posted by Randy Holmes-Farley
FWIW, limewater is all I dose for calcium and alkalinity.

Randy, thats not fair.

Since you do continuous water changes and supplement your salt mix to the correct proportions, I'm sure limewater takes care of your business.

A lot of these folks change water every two weeks to a month and just go with whatever calcium and alkalinity is in the salt mix. Then try to maintain with 2-part.

Big difference.

[Randy Holmes-Farley]

Actually, I suspect one big difference is that I do not have as much SPS as many folks, and I have quite a lot of evaporation. That said, many people do it.


ReefDreamz: the exact dose of limewater is not all that important. It is somewhat self correcting in that as you dose more the demand rises to match it. So just start something and adjust it if necessary.