Supplementing Kalkwasser with carbon dioxide -02/27/08
I just wanted to run this by the WetWebMedia crew for comment to see if there is any merit in my implementation of this approach. I have found that if Kalkwasser as added too quickly or too much there can actually be a fall in calcium levels even if you avoid a pH spike more than 0.2 
The chemistry goes like this...
When Calcium Hydroxide solution (Kalkwasser) is slowly dripped into your aquarium, it captures free Carbon Dioxide present in the tank water and converts it to Bicarbonate ions like this:
Ca++ + 2(OH-) + 2(CO2) <==> Ca++ + 2(HCO3-)
If you drip too fast or if there is not enough Carbon Dioxide available in the water, the Bicarbonate ions will be converted to Carbonate ions like this:
Ca++ + 2(OH-) + 2(HCO3-) <==> Ca++ + 2(CO3--) + 2 H2O
The Carbonate ions formed will make the Ca++ you are trying to add to your tank get wasted by the useless precipitation of Calcium Carbonate
So, too rapid addition of Kalk may actually cause the Calcium and Alkalinity in your tank to go down instead of up like this:
Ca++ + 2(HCO3-) + Ca++ + 2(OH-) <==> 2 CaCO3 + 2 H2O
In the above reaction, a Calcium ion and two Bicarbonate ions from the aquarium combine to form solid calcium carbonate.
This can happen even with a slow drip of Kalk if there is not enough CO2 in your water -- something you can't easily control.
I have an open top to my aquarium, 300 litres in the display tank, and 100 litres in the sump. All the corals are LPS corals. I loose 6 litres a day in evaporation. I have noted falls in calcium using Kalkwasser even if it is rapidly distributed in front of an 8000 litre per hour Tunze Turbelle pump.
This is what I have done over the last three months. The pH of my tank is consistently 8.3
Each day I mix up one litre of carbonated water using a soda stream machine, and add that into the tank. This will drop the pH of the tank to 7.8 But I follow this up a few minutes later with the addition of 5 litres of water mixed with 2 teaspoons of Calcium hydroxide over a 10 minutes. This raises the pH back to 8.3
<interesting>
I have checked these readings over a dozen times and the results are predictable. Adding 2.5 litres of Kalkwasser only pushes the pH up to 8.1 Adding 2.5 liters of Kalkwasser without the use of carbonated water will raise the pH to 8.5 (good for phosphate precipitation) I us Salifert test kits.
Over the three months, the calcium is steady at 340 and Alk 3.4 without the addition of any other supplements. Though the calcium levels are adequate, I would have expected higher levels.
<Maybe the calcium is being used up rapidly?>
So am I on to something here, or is my implementation and understanding flawed in someway?
<I think your chemistry makes sense... and your results make sense. However, I'm not sure how much (or little--or if at all) this sudden pH drop to 7.8 might be effecting things. To be frank/honest, we don't actually know all that much about all the myriad of potential chemical interactions that go on in a reef tank. Calcium can be sucked out of the water in so many different ways. It could be used up by organisms, or precipitated out (maybe even do to the increase in CO2 -this could possibly cause calcium carbonate precipitation). I'd encourage you to keep experimenting (in a separate tank maybe-- rather than risk your display/animals). And I thank you for sharing with us.>
Mike Lomb
<Best,
Sara M.>

Kalk Dosing... A Must To Accurately Measure/Monitor pH – 10/30/07
Howdy guys/gals,
<<Cheers Mike!>>
Just have a quick question I can't find an answer to.
<<Let’s see if I can help>>
I just recently traded a fish tank for a Stony Reef Kalk reactor (super excited!!!!).
<<Neat!>>
I don’t have an ATO unit or pH controller yet.... but wanted to get this thing into action!
<<Mmm...you can get by without an “automated” top-off unit (and I suggest the Tunze Osmolator over the ATO gear), but you will need to be able to closely/frequently monitor pH. I strongly recommend you put the purchase of a pH meter ahead of any automated top-off equipment, if finances preclude getting both>>
Input comment here LOL.
<<Comments inputted>>
Here are some quick specs -
100 gallon tank
ph - 8.2-8.4
SG - 1.025
Cal. 400-450
Alk 8-9
Mag - 1300
Mainly Acropora (10+ small-med colonies), Montipora (10+ small-med colonies), and one derasa (growing like no tomorrow).
<<Sounds very nice>>
It seems like they are consuming quite a bit of carb/bicarb, and Calcium because I test once a week and the numbers drop by 1 dKH and 50ppm calcium. I was thinking about setting a Tom's Aqua-Lifter pump on a digital timer for 1-2 minute intervals 2 hours apart, 6 times at night. The pump runs about 3.5gph so the dosage would be 1min - .058 gallons - or 2mins. - .116 gals. Is this going to be too much at one time??
<<Not likely>>
1/10th of a gallon seems like nothing in a 100gallon tank but do you think it would be detrimental to dose this quick?
<<It is always wise to be cautious, start small, and monitor continuously to determine the correct “dosage” of Kalkwasser. The water in the reactor can only dissolve/absorb “so much” of the Kalkwasser...as long as you are dosing the supernatant and not allowing solids to enter the tank then I suggest you set the pump and timer to replace “all” water lost to evaporation...i.e. – run all your top-off water through the Kalkwasser reactor. If you have an idea of how much water is lost to evaporation on a daily basis (and you should), then it is a matter of just doing the math to determine how long the pump must run to replace this. You could set it up to make the replacement overnight when pH typically falls...or space it out over a 24-hour period>>
pH spike ??
<<Thus the need for an electronic monitor...in my opinion>>
Suppose I won't know until I try it but my pH titration test kits aren't accurate enough.
<<You need to correct this or purchase a pH monitor before proceeding with the Kalk reactor>>
Any advice on how to get this reactor in action would be greatly appreciated. I really should just wait, I bet...
<<Until you can accurately measure/monitor pH...yes>>
Thanks – Mike
<<Regards, EricR>>

Bristle Worms, Calcium Reactors and Kalkwasser interactions
Hi Bob,
Thanks for your help/reply with my ?algae problem (CYANO AKA BGA). What I actually did is followed everything you told me to slow down the CO2 of the reactor, unplugged the 2nd power head that feeds to the reactor, did another 20% water change, while scraping off the algae off 4 sides of the tank, although it is hard to scrape on certain areas due to small space between the wall and rock. 
<I understand. Good work>
Besides having a UV(25watts) I also plugged the Ozone to the Berlin skimmer, which in my guess 03 would kill these BGA since it is considered a bacteria kept it at 350 with 25mg/hr. 
<Yes, this would help.>
I read an article on the web site link that I should also stop adding Iodine so I can starved them, but I'm afraid that I would also starve the Macro Algaes, and I know that Iodine supports the well being of both soft and hard corals as well, and for the shrimps to molt, so I'm afraid I have to add one tonight since I skipped last night. Anyway the final result was THE BGA seems to slow down a bit, and the Alk is now 9.5dkh instead of 15 last time, Ca is also down to 400 instead of 498ppm, 
<Very good... you will see improved results as time goes forward>
but I heard if you have SPS it should be above 400ppm, I have purple Montipora, and 1 yellow Porites is 400 ppm okay,
<Absolutely... natural seawater has a calcium level that is much lower than this...>
oh! I also drip Kalkwasser for water make-up and also to precipitate Phosphate
<What? Along with using a calcium reactor? Don't do this... a real source of trouble... and likely the principal source of your troubles... disproportionate loss of magnesium... at any length, cease the Kalk use>
that could be leaching from the additives and activated carbon. 
<Doubtful>
Anyway my biggest concern now is I believe it's bristle worm, I went to the site to check out pictures of bristle worm, but mine are small and so many that
they are all over the rock and corals, one of my finger leather, flesh was coming off and some areas are turning black. I read somewhere to use a glass
and place food so this bristle will come inside, and they won't be able to come out, have not tried that yet, i decided to buy a trap, along with 2
sixline wrasse. Somehow I thought I read something about this wrasse keeping the population of bristle worms in check. 
<Most of the time, small bristle worms species are no problem... and a proliferation of them an indication of something else amiss... too much food, lack of predatory checks...>
Here's the results, have not placed the trap yet, one of my wrasse died 2 days later because the bigger wrasse is a bully. Anyway what this wrasse do is eat the bristle worm the whole day and he has a big stomach and swims left to right eating every worm he finds, since I feed lightly now due to the previous BGA problem, I even saw the yellow tang swallowed bristle worm. I guess I solve 1 problem, but have another, which I read from the FFExpress Faq's that as long as the bristle worm are small it is okay and in fact they are beneficial (meaning that they will eat detritus I assumed, and they are part of the fauna).
<Yes...>
Sorry I ask too many question, but I just have one more (PLEASE!) I was planning to use the reef filler that I bought from Champion.
<Good idea>
My plan was to somehow figure out my evaporation rate and keep using the Kalkwasser slowly
<Just use clean freshwater... leave out the Kalk>
dripped and keep running the CA reactor because it's doing so good maintaining the Ca/Alk level, then Premixed my salt water (along with Iodine
and Trace elements) in a 40 gallon tank for1-2 days then transferring them to a big container like 180 gal drum, which sits for 2 weeks with powerhead
and heater at all time, and some how taking the 5% out from the sump and adding a 5% from the 180 gal premixed. This process is on a continuous basis,
but occasionally will clean the detritus out of the tank when necessary. I also bought a Tsunami AT1 auto top off, but can't figure out how it works,
<Contact them...>
I'm assuming that new water have to be the same level as the sump in order to work, but I'll have to try that. 
<Doesn't have to be the same level>
Is small frequent water changes better than a big monthly changes? 
<Yes... weekly probably ideal>
Thanks a lot Bob I don't know what to do without you! I heard you were planning to be in Monterey (some type of reef
convention) this year along with other DR's when will that be, and is anyone welcome to go?
<Yes... the Western Marine Conference... their link is on the Links Pages on the www.WetWebMedia.com site>
Thank you very much!!!!
Rommel
<You're welcome my friend... you're on your way to great improvement. Bob Fenner>

Kalkwasser and Cyanobacteria
Hello. 
<cheers, my friend. Anthony Calfo>
I have a 30 gallon reef set up right now. I have noticed very small bits of cyanoBACTERIA that I have been removing manually each time they pop up (infrequent and small, but still present every other week or so). 
<removed by slurping out with a siphon, right? not stirring up?>
I use RO water for top-offs and changes. 
<do aerate first and then buffer before using>
My friend who is a fish store guy, told me that using Kalkwasser not only helps with the calcium levels, but can also help (to a certain degree) with alkalinity and might clear out any Cyanobacteria. 
<he is very wise on these matters indeed. Agreed>
He has done this in his tank. My question is this...I was thinking about using a SLOW Kalkwasser drip in conjunction with Aragamilk to raise both calcium levels and alkalinity respectively. 
<I wouldn't bother with the Aragamilk>
Is there some danger to this with my mini reef? 
<not at all. Kalkwasser used properly is a great benefit. Simply never add so much that your pH jumps more than .2 tenths of a point in a short period of time. Test the first few times you dose to determine how much/how fast. Kalkwasser also improves protein skimming and precipitates phosphates. I wrote about the merits of its use in reef aquariology at length in my book>
It is not overstocked at all, and it uses the Berlin system (I emailed before about a couple of Anthias, but they reside in a 55 fish only). Meaning that I use a skimmer and LR for filtration with about a 3-4 inch sand bed made from aragonite. 
<sounds very nice>
I am looking to avoid swings in pH, 
<dose Kalk after lights are off then>
boost up calcium, as well as clean up the Cyano, but I am rather skittish about adding anything to my small tank due to the low volume.
<again, a simple matter of a concurrent pH test the first few times applied>
Currently I simply under-dose Kent Marine Iodine, Molybdenum and calcium on a bi-triweekly basis, which are all supposed to be able to be dosed with Kalkwasser. 
<go easy on the liquid calcium (chloride accumulates and is a nightmare in the long-run) and do add SeaBuffer to this program. You'll want an Alkalinity test kit too>
Any advice on how to approach starting this new Kalkwasser drip or on how to further avoid Cyano will be greatly appreciated. Thanks! Paullee
<best regards, Anthony Calfo>