Alkalinity and calcium

[Hannahhhh]

Hello,

I'm struggling to understand the relationship between alkalinity and calcium levels in my tank. I’ve read a ton about it but I’m still confused. 

I have a high level of calcium (500) and low alkalinity (7)

I’m not sure how to address this. I have B-Ionic calcium buffer system with component 1 alkalinity and component 2 calcium but I’ve never used it.  Can someone help me out? Specifically can you tell me what you would do in my situation. 

I have a 13.5 gallon fluval evo tank. I also have a protein skimmer attached

For coral I have some mushrooms and Xenia, a pink birds nest coral, zoas, and some leather corals. Additionally I have a coco worm (hard tube feather duster), a clownfish, 2 cardinalfish, and one tiny goby.   

 

[Hannahhhh]

Alkalinity is now 6.9. I did a water change yesterday of 25%

[xthunt]

Supposed to be that alk and cal get used up in a certain ratio (ideally), and the 2 part restores them in that ratio, so they’re made to be dosed together, equally. But if you think your calcium is high, want to lower it, and just want to dose the alk, that should be fine. 

 

Your saltmix might have high calcium, so might be hard to let it fall with water changes bringing it back up. 500 cal isn’t ‘bad’, Reef Crystals has more than that last time I checked, something like 540. Fritz rpm 460-480. 

 

Im using b-ionic and 1ml raises my dkh +1 in my 25 gallon tank (~19gal actual water), if I remember right. EDIT: 8.5ml to raise my tank 1 dkh, according to calculator. Im on a doser so forgot. 

[748S911]

I just dose kalkwasser in my evo with my ato unit, kalk +2 to be exact.  It keeps alk to 8+ and maintains your current calcium level.  So whatever your using for top off water mix in kalkwasser an hour before or more, let it settle and use that mix to top off your tank.  You could do it manually too... Just make sure you dont shake up the bottom layer of kalk. You just want to dose the clear liquid not the sediment on bottom. 

[748S911]

This way its not a pain to keep track of your parameters... with your coral load, I would do a 50 percent water change, then another in a few days to start at perfect levels that your salt mix comes with. Then with kalk mixed with your top off water you maintain your alk and calcium always with out having to mess with two part.

[748S911]

Oh and make sure you gradually add it in there cause its very strong stuff.  I wouldnt add more than two cups a day. 

[MrObscura]

What salt are you using?

 

Alk and cal are consumed at a balanced rate and it's usually waterchanges or dosing in unequal amounts that throws it off.  

 

First I'd double check that your tests are accurate. 

 

Then you should test your mix water and see where Alk and cal are. Then adjust your tank to match that. If cal is lower than your tank just let that fall naturally  until it matches your mix water parameters. If  mix water Alk is higher than the tanks slowly bring it up. 

 

After that based on you tanks demand water changes alone should keep things in line since youre mostly softies. 

 

When your dkh starts falling in a way that waterchanges can't keep up then either start kalk (research how to use it first) or dosing 2 part.

 

 

[Gravity]

I’m still pretty new to reefing so this may be a mute point. 

 

The nitrification process also uses alkalinity. So if you’re feeding heavy and producing a lot of nitrate that could reduce alkalinity but not calcium. However, I'm not sure how this consumption rate compares to coral uptake so the impact of nitrification could be minuscule. 

[pricewayne]

I won’t even claim to be a pro at the science or dosing calculations — but thought I’d call out time of day is significant when testing alk, ca, mag. A safe way to get a truly accurate measurement of your levels is to get a week’s worth of testing without dosing anything.

 

- test new saltwater that you’ve mixed (at same temp as your tank)

- test your tank alk, ca, mag daily at the same time of day, for a week

 

Once you do that, you’ll have a clear picture of your tank’s absorption rates and then calculate the daily dosing to keep water parameters stable 🙂

[streamline.by.design]

Check your Magnesium levels. If they are not in the right spot it will mess with the Ca/ALK balance as well. Get a salt that mixes lower and dose up, easier to do that than to drop levels...

[WindyCityReefer.]

I have been using the B-Ionic 2-part system for a couple of years now on my 25 lagoon and here is how I dialed it in.

 

Like PriceWayne suggested, you want to test your water for alk/calcium/magnesium over a week's time. It was easiest for me to test about an hour after a water change to create a "baseline" for where my levels were at and then daily after that until my next water change (I perform weekly water changes using Reef Crystals salt mix). You also want to make sure you are testing around the same time of day each day. By testing every day you will be able to see the rate at which the tank consumes the big 3 (alk/calc/mag) and how much of the 2-part you will need to add every day to keep them at those "baseline" levels. In smaller systems like ours, the likelihood of having to dose magnesium is small if you are doing weekly water changes because it is consumed in smaller quantities and most salt mixes replenish that amount (but do test to confirm!). 

 

Here is a great article that breaks things down. http://www.reefkeeping.com/issues/2004-12/rhf/

 

To answer your original question, if I were in your situation I would evaluate my salt mix and see what levels I am getting when I am mixing and doing a water change. Then from there decide if that salt mix fits my needs or goals for my system. If yes, then follow the above plan of testing weekly and figuring out how much the system utilizes and how much I have to dose to get back up to my ideal values of the big 3. 

 

Unfortunately, dosing is not a "set and forget" system like everyone makes it out to be. You should still test weekly to make sure things are in line and that the amount you are dosing is still adequate. Once corals start growing or you add more corals to the tank, the demand will go up drastically. Never dose blindly without testing!

 

The good news is that the B-Ionic system is tried and true and you should be able to achieve great success using it! 

[Nevvy]

Everyone is giving solid information. +1 on 50% water change to "reset" your parameters.

 

Then test water parameters a few hours after, next day at the same time test again, and continue testing the next 3 days or so and record the amount of ALK and CA being used by your system. Then dose accordingly to reach your wanted numbers.