High Calcium & Low Alkalinity

[falcooo]

Quick question...I was under the impression calcium and alkalinity went hand in hand, in such a way that corals consume both equally. However, I have recently added a some SPS frags and am starting to see my parameters shift. Today, Alk @ 7.1, Ca @ 460, Mg @ 1470. The past few months my parameters have remained stable @ 8.5, 420, and 1300. So if the stoney corals are consuming Alk, why are they also not consuming Ca? Can anyone shed some light on how/why Alkalinity would decrease but Calcium & Mag would increase?

 

As always, much appreciated!

[Clown79]

They work hand in hand but as 1 drops the other rises.

 

So to maintain them and keep them stable ppl often dose 2 part buffer.

 

 

[falcooo]

29 minutes ago, Clown79 said:

They work hand in hand but as 1 drops the other rises.

 

So to maintain them and keep them stable ppl often dose 2 part buffer.

 

 

Really!? Okay, well that makes sense then. So now that there's significant consumption, I need to start testing daily again to determine the appropriate dosage schedule going forward. I really had myself fooled thinking I was going to get by with only weekly water changes and no dosing. ?‍♂️

[A Little Blue]

This might help:

http://reefkeeping.com/issues/2006-06/rhf/#10

[markalot]

29 minutes ago, falcooo said:

Really!? Okay, well that makes sense then. So now that there's significant consumption, I need to start testing daily again to determine the appropriate dosage schedule going forward. I really had myself fooled thinking I was going to get by with only weekly water changes and no dosing. ?‍♂️

Yea, not with SPS.  The good news is they are healthy enough to be using it up.  Carefully dose equal parts of a good two part  and base the dosing off of Alk testing.  Let it run low, like 6.5 to 7 for a while.  They can survive too low, what you want to avoid is spiking Alk.  A quick jump from 7 to 9 will flat out kill them.   This is where most people new to acros (woops, looks like you are other SPS which is GOOD)  kill them so be very careful, under dosing is better than over dosing.  Keep calcium between 425 and 450 and you'll be fine.   Test it from time to time to make sure it stays in range, correct when needed.  As long as you are dosing equal parts two part calcium should stay in range.   Don't dose at the same time and if possible dose in different areas of the tank ... or in a high flow area of a sump.

 

Calculator:  http://reef.diesyst.com/chemcalc/chemcalc.html

[falcooo]

29 minutes ago, A Little Blue said:

This might help:

http://reefkeeping.com/issues/2006-06/rhf/#10

Very informative read. Thanks for sharing!

9 minutes ago, markalot said:

Yea, not with SPS.  The good news is they are healthy enough to be using it up.  Carefully dose equal parts of a good two part  and base the dosing off of Alk testing.  Let it run low, like 6.5 to 7 for a while.  They can survive too low, what you want to avoid is spiking Alk.  A quick jump from 7 to 9 will flat out kill them.   This is where most people new to acros (woops, looks like you are other SPS which is GOOD)  kill them so be very careful, under dosing is better than over dosing.  Keep calcium between 425 and 450 and you'll be fine.   Test it from time to time to make sure it stays in range, correct when needed.  As long as you are dosing equal parts two part calcium should stay in range.   Don't dose at the same time and if possible dose in different areas of the tank ... or in a high flow area of a sump.

 

Calculator:  http://reef.diesyst.com/chemcalc/chemcalc.html

Yeah, and I'm definitely new to SPS. After success for 6 months with LPS/Softies, I went ahead and added a couple monti caps and a few small acro frags.

 

Follow up question... Because I already have SeaChem's Reef Builder (alk) & Reef Advantage (ca). Though they are labeled as such, and not Part 1 & Part 2, are they essentially the same thing? Assuming I determine how much of each I need to regularly dose to maintain parameters. And now that calcium is high and alk low, today I dosed only Alk to level them out. That's correct, right?

[markalot]

7 minutes ago, falcooo said:

Very informative read. Thanks for sharing!

Yeah, and I'm definitely new to SPS. After success for 6 months with LPS/Softies, I went ahead and added a couple monti caps and a few small acro frags.

 

Follow up question... Because I already have SeaChem's Reef Builder (alk) & Reef Advantage (ca). Though they are labeled as such, and not Part 1 & Part 2, are they essentially the same thing? Assuming I determine how much of each I need to regularly dose to maintain parameters. And now that calcium is high and alk low, today I dosed only Alk to level them out. That's correct, right?

 

Yea, that's correct, but 460 calcium works fine with 7.1 Alk.  Matter of fact, that gives you a nice buffer for mistakes.  While the two are tied there is no best balance.  I linked to a video in another thread, and in my 150 thread, where WWC related how they run high calcium in purpose.

 

Reef Builder and Reef Calcium can work as two part but they aren't balanced so you'll have to use the calculator to figure out how much to use for each.  You could measure the daily drop of both and dose accordingly, I just find it easier to just test Alk and base 2 part dosing on that.  Always test calcium on a regular basis though ... I just went through a calcium accident because I didn't test and my doser was off.  270 calcium killed some acros.

 

I'll stress again, don't overdose, underdose.  it will be enough to keep the SPS healthy and you can slowly get to the correct amount over time.  

[falcooo]

8 minutes ago, markalot said:

 

Yea, that's correct, but 460 calcium works fine with 7.1 Alk.  Matter of fact, that gives you a nice buffer for mistakes.  While the two are tied there is no best balance.  I linked to a video in another thread, and in my 150 thread, where WWC related how they run high calcium in purpose.

 

Reef Builder and Reef Calcium can work as two part but they aren't balanced so you'll have to use the calculator to figure out how much to use for each.  You could measure the daily drop of both and dose accordingly, I just find it easier to just test Alk and base 2 part dosing on that.  Always test calcium on a regular basis though ... I just went through a calcium accident because I didn't test and my doser was off.  270 calcium killed some acros.

 

I'll stress again, don't overdose, underdose.  it will be enough to keep the SPS healthy and you can slowly get to the correct amount over time.  

Thanks Mark! That really helps. I've got a much better understanding now than an hour ago. 

[Aurortpa]

Here is the chart at which they believe dkh and calcium work at optimal balance--just came across this a bit ago.  My tank definitely eats up alkalinity faster than it consumes calcium, but the rate at which it does so has varied and has changed remarkably since I first started testing and dosing...for example calcium was being eaten up faster as well but then slowed significantly...so test regularly.  I test twice a week for alk and once a week for cal.  

 

[mcarroll]

17 hours ago, falcooo said:

Quick question...I was under the impression calcium and alkalinity went hand in hand, in such a way that corals consume both equally. However, I have recently added a some SPS frags and am starting to see my parameters shift. Today, Alk @ 7.1, Ca @ 460, Mg @ 1470. The past few months my parameters have remained stable @ 8.5, 420, and 1300. So if the stoney corals are consuming Alk, why are they also not consuming Ca? Can anyone shed some light on how/why Alkalinity would decrease but Calcium & Mag would increase?

 

As always, much appreciated!

This is a combination of hobby-grade test kits and basic seawater chemistry and stony coral growth.

 

The base of it is that there's very, very little alkalinity in the water compared to calcium or magnesium.  (200ppm vs 420ppm vs 1300ppm)

 

So when corals grow, alkalinity has a big swing where the swing (percent change) in calcium or magnesium is still small.

 

Here's the kicker.....the change in Ca or Mg can be so small that it can lie within the testing error rate of the kit, appearing to be no change.....leaving you to think that calcium hasn't been used at all.

 

This is partly why two-part formulations are "balanced" and why they often tell you do dose equal parts of each based on alkalinity test results. 

 

Once demand gets higher, then usage of calcium will be more apparent.

[falcooo]

As a quick update, I dosed SeaChem Reef Builder (alk) yesterday. I just got home from work and tested my water, Alk raised slightly to 7.3 from 7.1, and Ca dropped slightly from 460 to 440. I believe I should dose only Alk again today, right? That should bring me right back to 420 & 7.5, and at that point I will start testing to determine consumption and dose both Ca & Alk accordingly.

[falcooo]

Buying pre-mixed salt water from the LFS was great the first 6 months of setting everything up, as it gave me time to learn all of the reef keeping basics. But from now on I'll be mixing my own water. I think the drastic shift in parameters was from having a bad batch from the LFS during their transition to a new location. So I bought the same salt (Reef Crystals) they were using before because I was already having success. Now after a couple water changes and daily testing, I believe everything is back on track. I would image the shift from 8.5 to the mid-7's and 440 to 400 over the course of a week is considered pretty stable, right? I hope so.

 

9/26 - 7.1 & 460 *Dosed Alk

9/27 - 7.3 & 440 *1g Water Change

9/28 - 7.4 & 440

9/29 - 2 Gallon WATER CHANGE with my first batch of homemade salt water 👍

9/30 - 8.5 & 420

10/1 - 8.4 & 440

10/2 - 7.8 & 420

10/3 - 7.5 & 420

10/4 - 7.8 & 400

 

Note: All test and maintenance were performed at the same time of the day. 8PM, towards the end of full lighting just before ramping down.