Assistance getting started with Kalk/2 Part...

[Phyber]

Hi all! I have a newer mixed reef tank (about 75g total volume) and I'm looking into what would be needed for supplementation of Alk, Cal, and Mg. I am waiting on test kits to come in today, as up until now I have just been religious with 30% water changes every two weeks (IO Reef Crystals) at 1.026... My questions at this point are theory until I can get a pattern of tests done, but...

If I went with 2 part...
Let's say I do a water change, and afterwards I get a reading of 420 Cal, 8 Alk, and 1350 Mg. Everything's perfect, right? Fast forward to two days and I get a reading of 410 Cal, 7.5 Alk and 1320 Mg. This would mean that in two days, my corals have used up 20 Cal, .5 Alk and 30 Mg. If I wanted to maintain my "perfect" initial testing, I could refer to the BRS calculators and add their two part products to up my numbers back in range, or, do another water change and (assuming the mix was good) get back to "perfect", correct? Rinse and repeat every week, testing and dosing manually, or upgrading to dosing pump and then be testing and programming my Apex to dose over the course of 24 hours.

If I went with kalk...
Let's say I do a water change today, and afterwards I get a reading of 420 Cal, 8 Alk, and 1350 Mg. I have a 5g bucket that I use for my Tunze ATO, and I mix up a batch of the weakest mix kalk advised (2 teaspoons for my 5g). I typically evaporate about 5g a week in this weather, so in one week I test and see that I drop to 410 Ca, 7.5 Alk and 1350 Mg. The next time I fill my ATO, I mix in a little stronger kalk. I do a water change, and after the week of a little strong kalk, I see that I only dropped to 415 Cal, 7.8 Alk that means I'm closer to dialing in my kalk amount, correct? Will that amount ever change according to the size of corals or is it population of coral based?

This is my second round with reefing, and I realized some mistakes in my first...I liked to tinker too much, tried to add too much when not needed, etc. To me, the idea of dosing makes sense but just seems like wayyyy too much to keep up with. On the other hand, kalk seems simple but doesn't ever increase my numbers but instead just "holds what ya got", correct?

The alternative to this is not doing anything but water changes, possibly at the expense of corals not growing. I don't mind the water changes, but they do take some resources (time spent making RODI, space to store my Brute can, running mixing pump and heater, time to change water, etc.), and if I could dial in a dosing program that would like 2-3 months... that'd be great!

 

[MrWheelock]

Bump for some help. I dose redsea and use thier recommendations as far as dosing

 

[Kyuss414]

If I went with 2 part...
Let's say I do a water change, and afterwards I get a reading of 420 Cal, 8 Alk, and 1350 Mg. Everything's perfect, right? Fast forward to two days and I get a reading of 410 Cal, 7.5 Alk and 1320 Mg. This would mean that in two days, my corals have used up 20 Cal, .5 Alk and 30 Mg. If I wanted to maintain my "perfect" initial testing, I could refer to the BRS calculators and add their two part products to up my numbers back in range, or, do another water change and (assuming the mix was good) get back to "perfect", correct? Rinse and repeat every week, testing and dosing manually, or upgrading to dosing pump and then be testing and programming my Apex to dose over the course of 24 hours.

In this scenario, you would take note of your daily consumption, so 0.25dKH, since you dropped 0.5dKH over two days. Then yes, you could initially dose 0.5dKH to return to target level and essentially make up for that missed day, then each day after that you would dose the 0.25dKH for your daily consumption. The water change method would also be fine, but IMO not necessary

However, be aware that you don't want to make too drastic of a change to quickly. Say you test alkalinity and you get 6.0dKH, you don't want to dose for 2dKH in one day. 0.5dKH-1.0dKH per day is a better bet, with the lower end being a safer bet if you're keeping SPS coral.

Also keep in mind, if dosing sodium carbonate for the alkalinity supplement, this will raise PH as well. For this reason, most reefers will dose the Alkalinity supplement over night when using a dosing pump as PH naturally drops in a reef tank at night and this help stabilizes it a bit, or early morning before lights come on if dosing it manually all at once (again since the PH is lowest at this point.) Then dose calcium over the course of the day (doesn't affect PH with any significance) if using a dosing pump, or later in the afternoon if dosing it all at once manually. The reason for this is you want to give some time between dosing the alkalinity and calcium supplements to limit precipitation.

If I went with kalk...
Let's say I do a water change today, and afterwards I get a reading of 420 Cal, 8 Alk, and 1350 Mg. I have a 5g bucket that I use for my Tunze ATO, and I mix up a batch of the weakest mix kalk advised (2 teaspoons for my 5g). I typically evaporate about 5g a week in this weather, so in one week I test and see that I drop to 410 Ca, 7.5 Alk and 1350 Mg. The next time I fill my ATO, I mix in a little stronger kalk. I do a water change, and after the week of a little strong kalk, I see that I only dropped to 415 Cal, 7.8 Alk that means I'm closer to dialing in my kalk amount, correct? Will that amount ever change according to the size of corals or is it population of coral based?

Kalk can certainly change your numbers, if you overdose or under dose it. That said, it's generally not used to make corrections, just for daily consumption, mostly due to the amount you need to add to make any significant adjustment and the impact on PH it would have, as it raises PH as well.

Part of the trickery with dosing kalk via your ATO is that evaporation isn't always consistent, especially with the changing of the seasons, having windows open or closed, AC or furnace running, etc. One method around that is to essentially dose fully saturated kalk for your given Alk/Ca needs, and run the ATO separately. What I've done before is dose the kalk for a given amount to meet my tanks demand. I had it setup to dose on the hour (ie. 10pm, 11pm, etc) and then my actual ATO pump run after that (ie 10:15pm-10:30pm, 11:15-11:30pm, etc) to make up any difference. This just made it easier IMO as I was always dosing a consistent amount of kalk day to day, month to month, and if/when I needed to make an adjustment I was just changing the amount on the doser rather than fiddling with concentration amounts. Just easier to calculate IMO.

Now that said, a well stocked SPS tank that has a high Alk/Ca demand can get to the point where you're adding more fully saturated kalk each day than you have in evaporation, even if 100% of your top-off is done with the kalk. In the method I suggested above, I could easily tell if I was reaching this point, as I could just look at my ATO reservoir and see if my tank was still calling for it on top of my kalk additions.

As for the amount ever changing, it most certainly will as corals grow, or even coraline algae starts to take off. That said, corals don't grow so fast to where it's going to be wildly changing consumption daily or anything. Once you get into a bit, you'll get a feel for your tank and when you'll likely need to make an increase. That's not to say to skip testing, but to know when to test so you can calculate your dosing adjustment. Starting out, you'll be testing daily to see the trend, start your dosing. Then every other day or so to make sure it's consistent. Then you can dial it back to once a week,or possibly once every other week once you start seeing the trends, etc.

Now, with all that said , it's definitely simplified, so I suggest checking out http://www.reefkeeping.com/issues/subject/chemistry.php as well once you have a general grasp on it. Randy "wrote the book" on most of this stuff. Even if your eyes glaze over when he geeks out on the details, it's still worth skimming the articles as he still takes the time and is really good at breaking it down to explain it to non-chemistry people.