Cal and ALk ?

mega · Jul 14, 2014

So my alk and calcium has been bumping around mostly my alk, calcium went from 500-400 in a period of two weeks, alk on the other hand went from 14-12-10dkh in a 2 week period or so. Just wondering what could be causing the problem went from dosing every day to every other now to stopping and just starting again on a 10ml dose of both alk and cal. When i dosed today that much the 10ml it jumped a lot for such a little dose. Let me know what you think, ive never really had a problem like this before, mostly zoas and lps in the tank.

b_rad_G · Jul 15, 2014

A drop of 2 dkh should only have approximately 20 ppm of ca. Corals use 1 meg/l of alk per roughly 20 ppm of ca. I am not sure the exact conversion but I think 1 meg/l is roughly 2.5 dkh. I don't dose 2 part so I'm not sure if you are supposed to dose equal parts to maintain balance. Also you should be dosing ca and alk at different times if you're not.

Pete polyp · Jul 15, 2014

1 meq/l=2.8dkh

mega · Jul 15, 2014

yeah i am dosing a different times, its jsut weird how its boucned around that much, did lose a sps colony and some zoas are acting up...

b_rad_G · Jul 15, 2014

Ya most sps are going to need more stable levels. I don't know much about a 2 part dosing system because I have never used one. Maybe someone with experience can chime in!

fishroomlady · Jul 15, 2014

I'm wondering if you need to be dosing with primarily lps and zoas. How often do you do water changes?

clownfitch · Jul 15, 2014

fishroomlady said:
I'm wondering if you need to be dosing with primarily lps and zoas. How often do you do water changes?

This was my first thought as well. Doesn't coralline algae also consume calcium and alk?

Reefing Madness · Jul 15, 2014

Depending on how large those LPS corals are, id think that water changes alone woukd be sufficient for that tank. Coralline will consume alot of alk if youve got a wall covered with it and the rock is virtually covered.
Whats your Mag doing with all this happening? Thats the one you want to test first and get where it needs to be.

mega · Jul 15, 2014

Do a 10 gallon water change in the system 110 gallons total, the mag is about 1400

mega · Jul 15, 2014

I have 35 zoa colony's some sps and a bunch of torches and stuff so not much using cal

Reefing Madness · Jul 15, 2014

SPS and the LPS will use both cal and alk, but it woukd all depend on how many you have and how big they are. Have you tried not dosing and just letting the water changes bring up the levels? Whats fhe initial numbers after a water change? Then again after a few days? Does the cal drop under 380? Or the alk under 7?

mega · Jul 15, 2014

no the calcium dropped to about 400, and the alk actually went up to around 10.9

Reefing Madness · Jul 15, 2014

Did you have your water double checked? What test kit are you using?

mega · Jul 16, 2014

salifert test kits did 3 tests in a row throughout the day

fishroomlady · Jul 16, 2014

I would say with that information, I may not dose but just be real consistent with water changes. I think you'd have less variability than dosing. I might also suggest you can drip kalk as a way to maintain calcium. It's much easier and less involved than dosing two part.

jduck · Jul 16, 2014

I would watch the alk. Sps especially don't appreciate it much over 10. And you need to look at keeping it stable, they also don't appreciate swings in the parameters.

mega · Jul 16, 2014

i wont drip kalk did it on an old tank and had nothing but problems with alk swings. im just gonna watch the parameters and see what happens and go day by day on this

mcarroll · Jul 16, 2014

mega said:
So my alk and calcium has been bumping around mostly my alk, calcium went from 500-400 in a period of two weeks, alk on the other hand went from 14-12-10dkh in a 2 week period or so. Just wondering what could be causing the problem went from dosing every day to every other now to stopping and just starting again on a 10ml dose of both alk and cal. When i dosed today that much the 10ml it jumped a lot for such a little dose. Let me know what you think, ive never really had a problem like this before, mostly zoas and lps in the tank.

fishroomlady said:
I'm wondering if you need to be dosing with primarily lps and zoas. How often do you do water changes?

mega said:
I have 35 zoa colony's some sps and a bunch of torches and stuff so not much using cal

mega said:
salifert test kits did 3 tests in a row throughout the day

I know you say you're testing, but there's no way you'd have mysterious jumps and drops like this if you were doing it "right".

You should be testing calcium and alkalnity and using the numbers you get from there to plug into the Reef Chemistry Calculator.
The RCC should in turn should tell you exactly how much to dose as well as some essential dosing advice, which you should be following.
The quantity you dose should be dosed slowly...something around a drip per second or less, depending on conditions.
You should watch your alkalinity drip very closely when you start it -- it's common for there to be a tiny cloud of precipitation created as the drip dissolves out into the tank water. You do NOT want to drip more alk into one of these little clouds or you will without a doubt be creating chalk out of the alk solution and calcium in the tank water. Time the drips so that the next one doesn't fall until the cloud has significantly (99%) dissipated. (Increase flow in the area or dilute the drips as needed. I dilute by up to 150% in my dripper.)
Remember that water changes also affect your numbers, so be aware of the calcium and alkalinity numbers of the salt mix you're mixing.
Until you are comfortable with a routine, I would test your system water for calcium and alkalinity before and after dosing as well as before and after water changes so you can see the exact effects of your efforts. (It shouldn't take long to get a feel if you are rigorous at the start.)

And as others have said, consider that you may not need to do any dosing on this tank. Consider switching to a fortified salt like Reef Crystals if you aren't using one altready - it may be a big help.

jduck said:
I would watch the alk. Sps especially don't appreciate it much over 10.[...]

That is false. Are you thinking of tanks which are carbon-dosed maybe? (Seems like "everyone" does that, so would be understandable.) Those are the only folks who have such a limit on alkalinity in keeping SPS.

SPS should be happy anywhere from NSW levels up to around 15 dKH or higher. 4 meq/L or around 11 dKH (with balanced Ca) is a great place to keep SPS if you're not dosing with an automated doser....gives quite a bit of headroom for coral-growth without danger of getting into an alkalinity range where pH swings can become a problem. If you do run an automated doser of some kind, then you have a different story....but the SPS don't care either way. As far as they are concerned, stability is king vs any particular number, as you noted too.

-Matt