Stony corals: how does kalk work? The lazy man's way to reef.

[Sk8r]

Stony coral: any coral that has a hard skeleton. The two types are sps (small polyp [mouth] stony) and lps (large polyp stony). SPS take a bit stronger light than lps, and a good skimmer: since they mainly eat light, very clear water is a must.

The other must for any stony coral, lps or sps, is calcium supplement. Your salt mix and water changes won't be enough. These corals sop up an amazing amount of calcium, and a smallish feeding hammer coral can suck the calcium out of your salt water literally overnight.

Kalk is literally calcium powder. The good thing is, a) it's real cheap and b) it self-measures. You dump a cup into your 5 gallon topoff reservoir---and stir it once. Water can only 'carry' so much of it, ie---only the 'right' amount WILL dissolve. The rest will form a white paste at the bottom. You have highly calciumed water, now, feeding into your tank. And if you have a tank that's in the 75 gallon range, this is all the calcium your corals can want. [Big reefs have to get aggressive and FORCE water to carry more, using a calcium reactor---but little reefs are just fine forever with kalk in a LIDDED topoff bucket. [Air makes a film on the kalk in the bucket].]

There's only one catch: you have to start with your salt water in good shape. 3 minerals have to be in balance to make this work. You test your tank's magnesium level first. Get it to 1300, first, and remember---you don't 'instantly' dose up to a level---wait several hours to retest, and if not enough, add more, wait several hours, retest---you get the picture. The next step, probably the next day: test alkalinity. Get it to 9.3 by stages. The third step, again, test your calcium. [never add calcium supplement and alkalinity buffer together: you get a snowstorm.] You want it at 420.

Once your tank is at these readings, put the kalk in your topoff bucket, be SURE your topoff pump is sitting on something to keep it out of the white paste at the bottom; also lid it (cut a notch for your pump cord and output hose: use foam rubber for a gasket) and let 'er rip. Check your water level in the bucket and always refill before the water runs out. When there's no more white paste in the bottom, add another lot of kalk. Test your magnesium level in your tank at least every 2 weeks, but don't worry about your alk and cal. Those CANNOT fall so long as you don't let that bucket run out of water and kalk--- And as long as your tank doesn't run below 1200 on magnesium. That's your 'safe' zone for magnesium---1300 to 1200.

When you finally goof and let your tank-magnesium run out or let your bucket run out of water, you have to test your tank water and get it back in shape, then re-set-up your topoff/kalk system and then go merrily back to your lazy occasional-testing, no-dosing ways.

I have a 32 gallon trashcan as my topoff bucket. I can leave town for a month and know that my corals are going to eat just fine, if my tank sitter just pours 3 buckets more ro/di water into the trashcan in the second week and drops food cubes into my tank for the fish.

[BDean]

nice write up

[Sk8r]

So you know what kind of a reef this system can feed---here's my tank.

[John_B]

Is there a way to drip kalk without a sump?

[stingythingy45]

Originally Posted by John_B

Is there a way to drip kalk without a sump?

It's can be done with Kent type drip containers.Or even as an auto top off system with a slow pump like a peristaltic pump or aqualifter.Biggest issue with kalk is adding it too fast.
I've been doing it for a couple years now.
I'm lazy.......

[Sk8r]

A gravity drip would work in a very, very small tank: there are things used for lizard watering systems (pet store) that actually let you dial-a-drip to adjust the rate. If you know how much your system evaporates daily, and adjust the drip rate to do that amount in 24 hours, you could do it. One catch: you have to measure the kalk, because those things feed from the bottom of the bottle, and you can't have white kalk paste coming down---if you mix 2 tsp per gallon, let it settle, fill your bottle from that---then you'll not have any white slurry, nor will it settle out of solution. It could be prone to clogging. OTOH, if you're a larger tank but just sumpless, just as stingythingy said, you can install a small float switch in your tank. When the water level falls, it will trigger a pump to jet a teaspoon or so into your tank---kalk or not, if you're living without a topoff, you'll like not having to top off daily, and your critters will be happier, too.

[Meshmez]

I started using kalk in my topoff about 2-3 weeks ago. Im mixing it at 1tsp/gal and its holding my levels nicely. If I were to add more kalk so that the water was saturated, would it start to raise the alk and cal levels in my tank? or would it still somehow even out?

[Sk8r]

Test your calcium level as per above. If it's 420, you're good at 1 tsp, but if lower, up it. Since you don't state tank size and how extensive your corals, I can't give better advice than that. When corals are new and not feeding much, or are sitting in a calcium-poor tank, they kind of shut down and don't grow much, and therefore the calcium-magnesium level doesn't drop very fast; but if you're at 420, with a temp between 78-80, corals should start feeding, and if you were hand-dosing calcium alone in a 50 gallon reef, you'd be pouring it in daily by the heaping spoonful. At that point, you would see the 'head' type corals start to divide, and double in size, and they can do that fairly often. That tank of mine started with a tiny little 3-head frag back in 2004, including a house move in 2007, and I've traded off about half of the volume you see in the picture---ie, if I had a big enough tank I'd have twice as much. You get to a stage where many of the heads are dividing at once, and a clump the size of a baseball can double over a few months: hammer coral is one of the fastest growing, when it's happy. So is montipora and poccillopora, among the sps types. [Monti and pocci are the equivalent of green star polyp among sps corals.] Frog doesn't grow as fast as hammer, and caulestra is way slower, at least at my parameters...OR the hammer is being chemically aggressive and suppressing the others: this can happen with corals, too.

[Meshmez]

My point/question is that 1tsp/gal is holding my parameters steady for now Cal:440, dKH~9.5, which means it is keeping up with my current growth. My question is, would adding more kalk to my topoff (fully saturated as in your description) increase my cal/alk, or would everything still level out somehow. (I know kalk in ato is to be considered a maintenance method, not a upping parameter method)

I ask this because if it does continue to increase the cal/alk, then if someone decides that they will start running kalk in their ato per your instructions, with one little sps frag in their tank, they will quickly drive their parameters high. If it somehow evens out still then no harm in running saturated ato before you need it other than wasting kalk.

[cjk76]

Sk8r, as many write-up and stickies as you have, I figured you to be the 2000g SPS dominated types. Nice to see another LPS fan!

Also, thanks for the Kalk tips. I've been meaning to start, but was worried about what all it entailed. Sounds pretty simple!

[RtReef]

I've been wanting to do this but for some reason I can not get my alk above 7-8? Calc is steady around 440 but alk won't go up. I've started adding a alk buffer and will soon start kalk once I get the alk up.

Thanks for the write up. Seems easy enough. How much kalk do you add at one time? I manually top off about a 1/4-1/2g per day.

[Meshmez]

Originally Posted by RtReef

I've been wanting to do this but for some reason I can not get my alk above 7-8? Calc is steady around 440 but alk won't go up. I've started adding a alk buffer and will soon start kalk once I get the alk up.

Thanks for the write up. Seems easy enough. How much kalk do you add at one time? I manually top off about a 1/4-1/2g per day.

Have you checked your magnesium? As stated in the OP if your mag is low you wont be able to bring the others up correctly.

[danil]

Kalk is great and thanks op for his great post to share his kalk experience. Few things to note though.
1. It's not fully 'self regulated'. You can add too much or not enough. Talking about Kalk 'self regulation' I would talk about correct ratio of Ca and Alk kalk provides.
2. If demand is low you might add less kalk and water wont be fully saturated.
3. If demand is getting higher (you have some growing sps corals and tons of coralline algae) Kalk can show it's limitation. Even with fully saturated ATO water you cant add more then evaporation volume. At this point some install extra fan to increase evaporation, some add vinegar to kalk, some just start supplement with two parts along with kalk.
Just to give you idea when kalk is about to be 'not enough' I had to switch to two part when I had two medium monti caps, few small milli colonies, medium to big frogspawn, one 4'' clam, some sps lps frags. I was running a huge fan under my MH and levels were still dropping so I had to switch.

[rovster]

I'll just add my experience. I kind of go against the grain and add it manually. I know that is not indicated and definitely not recommended, but let me explain. I got my parameters in check with dosing. Mag 1300+, Alk 8-9, and Cal holds around 410-420. Its a small biocube and with the lid, the evaporation is very minimal. I keep the Kalk in a lidded gallon jug and top off in the morning and at night. Its a TINY amount. Before doing it this way, I would top off every few days, but doing it twice a day, lets me just add a tiny bit. Probably about a 1/4 of a cup at a time. If I forget, and I need to add more, I just top off with regular RO knowing that I don't want to add too much at once. Parameters have been holding well. I have a monti, pocci, and cyphastrea that is growing like crazy. My hammer and other LPS look happy, but have not grown a whole lot. My hammer finally split a head after 5 months in my tank.

Anyway, I just thought I'd add my experience. I think because its a nano, I can get away with what I'm doing. Comments welcome, good and bad

[Sk8r]

By 'not measuring,' I mean that fresh water can ONLY dissolve a correct dose, which amounts to 2 tsp per gallon. You cannot get fresh ro/di to carry more than that, so you cannot overdose it. The rest will settle as a white slurry on the bottom. I have a 32 gallon reservoir, so I just dump in a pound of kalk now and again. I have my pump set up on eggcrate so it never sucks water from the bottom, where the slurry is. It will not overdose.

You should never, ever, ever dose freshly stirred kalk, because that will carry along bits of undissolved kalk, ie, the slurry. After mixing once, let it settle for 8 hours before using it, and never stir it again. A kalk stirrer is sold to the unwary, but is not a good thing unless you have sprung for a kalk reactor, and even so, ime, skip the reactor and use a bucket: it's cheaper, it doesn't break down 3 times a day. I had a 300.00 one and chucked it and two pricey stirrers in favor of a trashcan.

THere ARE kalk accidents, which amount to a topoff accident. It looks awful, cloudy white tank, etc, but your REAL problem is a) it's a topoff accident---fresh water has been added in a big overdose. Check your salinity. b) kalk comes in at ph 12, so if it was a really BIG topoff accident, ie, a real runaway, a teaspoon of Schweppe's bar soda per 50 gallons of tank water will start calming it down. Once mixed with salt water, the kalk very rapidly drops in ph, so if you do use that soda remedy don't overdo it, or the natural self-correction will combine with your fix and drop the ph too far. I've had accidents with it in a reef, no ill effects, no specimens and no fish lost. Of all dosing you can do, it's about the safest.

[Lynxone]

Great post! Thank you.

[Bnortz]

Very helpful. I have a few questions.

My tank's params are a little goofed right now. I have an ATO I need to set up soon, probably this weekend. Anyways, here are my params.

Calcium: 510 ppm
Alk: 6 dKH
Mag: 1400+ ppm

I obviously need to raise my alk, and somehow let the calcium and mag drop down.

What is my best option in stabilizing? I have an ALK buffer that I could use in topping off before I start kalk. I'm just unsure of how much to use per gallon of water. Right now I'm topping off about a gallon or so a day in a 60 gallon tank.

Also, in terms of my ATO, I have a 32 gallon trash can and I'm using an aqualifter pump. How full should I fill my garbage can be and how much kalk should I start off with once my params are set...?

[JMurphy97]

Would this work for tanks up to 120g?

[bnumair]

sk8r does kalk mixed in water produce equil amount os calcium and alkalinity or is it just calcium. i didnt read anything on alkalinity in ur forum.

[mess7777]

Can you provide more information about how Mg fits into the picture. I also have a dilemma that my Red Dea Mg test showed 1100 where the LFS test(Salifert) showed 1470. That's a large disparity, and since I didn't actually do the Salifert test I am not sure it was done right. Anyway, I digress, what problems does low Mg cause to this method?

[Augustus]

Just curious, I know sk8r said he tossed his but if its as simple as dumping kalk into your topoff water, why use a reactor?

[bnumair]

i know i can trust salifert over read sea anyday. Mg plays referee between alk and cal. if mg decreases it throws cal and alk out of wack too. Augustus sk8r is a she lol . reactors are required as this method here is not good/consistent over 75-90 gal tanks.

[Sport507]

Excellent write up as always Sk8r.

I have to use extra saturated kalk/limewater (another topic) because of the high demands in my tank and even then, I have to dose a little alk and cal but very little these days. Thanks you Mrs. Wages pickling lime, which I get at the grocery or Wal-mart.

I set my DT tank up on the 20th day of Oct. 2010 and the corals I started with were very small frags, so I frag more and more also added some from time to time and they were small.

When it come to reef tanks good chemistry is pentacle. A couple of pics taken just now the DT 90 and my 28 Bow and of course my friend too.

[JMurphy97]

Originally Posted by bnumair

reactors are required as this method here is not good/consistent over 75-90 gal tanks.

Not good because I was hoping to upgrade to a 120. I guess a 90 is not so bad right?

[bnumair]

Originally Posted by JMurphy97

Not good because I was hoping to upgrade to a 120. I guess a 90 is not so bad right?

well if u use a salt that maintains good parameters and if u keep an eye on ur alk and cal u can get away with this method by just stirring kalk in ur ATO. but if it falls short u can always manually dose cal or alk into the tank. it all depends on ur bio load how much alk and cal is being consumed.