Hand dosing Kalkwasser

[RandyFolds]

For the last 4 days, I have been hitting my 29G with an experimental .4g of Kalkwasser twice a day. I am far to lazy to rig up a drip system, so I have just been dosing the .4g (about 1/8 tsp) dissolved (or mixed rather) in a cup of DI straight into a high flow area of the tank.

The average healthy and well buffered system can take about .8 grams/50 gallons/hour without CO2 dosing, so I figure I am fine there. Are there any drawbacks to hand dosing kalk or to a very short duration drop in the pH (since I am dosing actual kalk vs. saturated kalk solution)?

I have not seen a reaction from any of the fish or coral in the system (other than massive growth from my montipora collection)...polyps don't retract or slime or anything, but it seems like my CBS starts running around each time I dose. I guess it could be that I am dosing at "dusk" for the system, and it is his most active time, but who knows...

[RandyFolds]

And while I am on the topic of calcium additions:

Bill - I tried discontinuing the calcium supplementation that I had been doing on the 29g to test your theory that dosing calcium is a waste of money. I should have been testing the levels, but that is a lot of work and I am a lot of lazy, so i merely relied on observation for the experiment.

The tank is stocked with plenty of SPS and a clam, all high calcium demands. After about five weeks of not dosing calcium, the coral vastly outcompeted the coralline algae cover causing it to decalcify and eventually, cease all growth. There is about 1/20th of the amount of coralline cover in the tank now, but the corals have shown serious growth continuously.

So, I was seeing daily, measurable growth in most of my SPS corals, but a complete cessation of coralline algae growth. Now that I have begun dosing calcium again, we will see if there is growth of the coralline, and if the growth of the SPS pick up.

[psykokid]

If you want a drip system i picked up two 1 gal kent aqua dose systems from a guy the other day and cant see myself using more than one for any reason. you're more than welcome to it, dilute out your kalk solution and use it as a slow top off if all else fails since its a gallon container..  As far as the calcuim uptake/usage i have no input on that one..

[Bergy]

interesting test, although i wish you would test the calcium/alk to see if you can measure a drop in between water changes...

The corline is an interesting observation too.. im wondering if it is 'precipitating' or something into coraline... ????

[Just_Greg]

that's how i used to dose my reef, Lanny.  never had any trouble, but it was a mixed softy/LPS/clam reef.

i can tell you that along similar lines, we pre-buffer our RO/DI water, both for top-off's and mixing SW.  our snails really grow new shell like crazy and the coralline growth is NUTS (remember we're only running FO setups ATM, but i thought it worth mentioning).

[RandyFolds]

interesting test, although i wish you would test the calcium/alk to see if you can measure a drop in between water changes...

This is my "no water change" tank. I guess I did about a three gallon water change to siphon out all the red planaria that are swarming it right now, but other than that, no water changes in over a year. Let me work this kalkwasser experiment for a month and then I will quit again and test it every couple days so we can settle it once and for all.

One of the reasons I started the kalk experiment was to reduce the phosphate in the system (kalk precipitates phosphates) and cap the growth of these damn flatworms so I can siphon enough out to treat the tank with some flatworm eXit.

Greg - what do you pre-buffer with? I remineralize/buffer my topoff water with AragaMight or Aragamilk, which are <15 micron powdered aragonite IIRC.

[Bergy]

well if it is a no water change tank then you will need to dose stuff as it gets depleted...

but, knowing how much to dose is the question...

you can use your observation to make some reference, but, unless the goal is to see how quickly you can grow coraline, then i am not sure what you are using as a determination

[RandyFolds]

When all your coralline algae decalcifies and your SPS corals are still growing, it is indicative of some serious calcium depletion and the corals are out-competing it, meaning the actions of carbonic acid dissolving aragonite in the tank can't even keep up, which usually sufficient (in a system without many fast growing corals) to keep the calcium concentration at around 300-350ppm.

To see rapid growth of both corals and coralline, I have to dose calcium often. I was adding 10ppm overall (assuming Seachem's claims about the AquaVitro line are accurate) every other day and never measured above 380 nor had a precipitation event, and would usually measure 320-350ppm. That means I was consuming at least 5ppm/day, which means - in theory - I could go about 20 or 30 days before the calcium was approaching critically low. I went about 5 or six weeks and saw a crazy amount of decalification of coralline, as well as very obvious dissolution of a bunch of empty shells lying around the tank. I have been meaning to post a pic of that for a while. The shells only have a crazy framework of the thickest parts left.

I should have tested it at least once when I knew it was crazy low. All this is just transitive assumption without the numbers, though I have known the coralline decalcification scenario to exist in other systems.

[Just_Greg]

FWIW, we pre-buffer our RO/DI (Seachem Reef Buffer) and the coralline growth in our systems is beyond crazy.  of course, we're not keeping anything else besides snails, which also are packing the shell on as well.

[Bergy]

what is it buffering???

and have you measured, before buffer and post buffer???

both the tank water and the water you are adding???

[Just_Greg]

we run our pH at 8.3.  IME, if you do a lot of top offs, your pH can be impacted by adding RO/DI that runs at 7.0.  once we began pre-buffering, the pH squared right up and is pretty rock-steady.

[Bergy]

makes sense...

the key words being if you ADD A LOT

this is a relative determination, so, if by chance your evaporation is a high ratio to your tank volume you should monitor and buffer the pH...

thanks for the clarification