kalk question?

DRC Archive General Saltwater Discussion
21

Back to basics and a little history. As I understand it, early reefers used limewater to both suppliment calcium and alkalinity in basic low load reef tanks. Lime water, while very high in PH(12.5) is low in available calcium concentration. but for low load tanks it was fine for calcium make up, PH control and alkalinity.

as we move up to higher demand, more dense hard or SPS coral populated tanks, we need more Ca and Alk plus PH boost. the Calcium reactor disolves CO2 into water to make carbolic acid, which disolves the aragonite media to make a carbonate solution. it disolves the the rock. acid on base. but a properly sized Ca reactor can only maintain Ca levels in the tank. not boost it. so you dose the tank first to desired levels and then start and balance the reactor. that works fine too for certain levels.

but if you try to boost the Ca output of the reactor you get an acidic solution with unreacted carbonic acid. this will be feeding a LOW PH calcium solution to the tank, and lower your PH. Low PH makes it hard or impossible for the SPS corals to take calcium from the water. so Reefers also use a Kalk reactor to dose high(12.5 PH ) hydroxide solution at night, to the tank to bringthe PH back up so the corals can use the Ca and CO3 from the reactor.

thats as near as i know. Hope i got it pretty much correct.

Oh adding vinegar(acedic acid) to a Kalk mix drops the PH which alows more CO3 and Ca to disolve into the solution, thus boosting the CA addition a little. It helps. but adding a second aragonite media chamber to the outflow of the Ca RX will insure all the carbonic acid is nutralized and max Ca and CO3 produced at a higher PH.

That is kinda why all these schemes are used for various demand tanks.

like i said, i have never used Ca Reactors, but have dripped some Mrs. Wages Pickling Lime water for PH boost. and we only grazed on the problem of precipitation of the good stuff out of the water. high concentration levels of PH or ALK or calcium can make everything solidify and and chemically combine to preciptate out of solution. and thus lower all the levels we were trying to raise.

so all things in moderation, including Moderation.

Hope this helps guide you a little.

22

soo much in this hobby to learn…anyone got any good links on this topic?

also does anyone have the Live Sand book by Dr. Shimek—thought id try :slight_smile:

23

I’m going to do one of those annoyingly long posts. ;D

Here is a post I did awhile back on kalk.

http://delreefclub.org/index.php?option=com_smf&Itemid=28&topic=1468.0
Link to RG about kalk. http://www.reef-geeks.com/forums/showthread.php?t=578

Not that I have a high load tank, but kalk (at least the stuff I use) provides plenty of ca and alk, to not only maintain my numbers, but raise them.

Just watch your alk and Mag #s, if you don’t dose Mag you should start if you drip kalk, as it will precipitate it out (high PH).

Here is a GREAT article on kalk and how it may lower your ALK and CA, and how you mitigate that with vinegar (and adjusting your dosing rate)
http://www.reefscapes.net/articles/breefcase/kalkwasser.html

As I understand it from what I’ve read and my personal knowledge (no I’m not a chemist either and don’t claim to be).

pH is a crazy scale, each number higher is 10 times less the amount of hydrogen ions or vice versa. The vinegar isn’t enough to make much of an impact on the PH of the kalk mix. Benefit: You still get the high pH.

pH - pH, the power of hydrogen

Benefit High pH - Precipitates impurities (phosphates as well) out of solution, maintains your pH at night.

Downside High pH - Precipitates things out of solution!, a main concern is magnesium carbonate will be precipitated out from the high pH zone where you drip it in. Keep an eye on the mag.

Benefit Vinegar - Allows more kalk to be used, allows more of an effect on Ca and ALK, food for bacteria to eat nitrates and phosphates. Helps keep your kalk container/doser/lines clean.

Downside Vinegar - Your getting into carbon dosing! Becareful. All of the same dangers are here.

Benefit Kalk - Can help maintain and in some situations raise Ca and ALK levels, while helping maintain a high pH at night, while precipitating out some impurities, while feeding beneficial bacteria (if using vinegar)

Downside Kalk - Can be overdosed. May not be the only solution to maintaining Ca and ALK. Will need to dose Mag more. Not as clean to work with.

I assume everyone can take some shots at what I wrote, enjoy. PBJ!

24

Ian, I am not arguing that it is how it is supposed to work… just saying that every time I have tried to dose it (5 or 6 times) it has made my alk drop and showed no change in Ca. I’m not sure if I was doing something wrong, but I have a much easier way to do it now (for me at least). A Ca supplement, a buffer, and a Mg supplement. Since its only a 20g at the moment it works fairly easily for me and I know how much of an impact each supplement should be used.

25

It’s whatever works and is easiest for you! :wink: As with everything in this hobby, there are many ways to accomplish our goals and no one way is right.

Not trying to argue at all, just laying it out there. I was also curious as if you used vinegar in your kalk at all, how it was sealed and dosed.

Check out the reefscapes.net link I posted. It describes how kalk can lower your alk and how vinegar can stop that.

26

No, I didnt use vinegar, as on a tank this size it would be fairly easy to overdose a carbon source… dont wanna mess with that right now. It was sealed in an air tight 5g bucket, and was dosed with a modified version of the ATO that was on keleigh’s tank. This design had 2 tubes instead of one. One to let air in and one to drip in the kalk.

27

I’m wondering if part of my problem was old Kalk. Perhaps if it had absorbed water from the surrounding air over time it causes a different reaction?

28

Old kalk can absorb ambient moisture and ambient co2 (the moisture facilitates this process), making it less potent and I would assume would run into some of the same issues laid out in that article, but I’m not sure. My stuff is pretty fresh :slight_smile: