Alk & Mag being consumed; Cal holding steady??

[Phyber]

75g total water volume tank is about 5 months old, and I've been religious with a bi weekly water changes of 20 gallons of Reef Crystals mixed to 1.026.

I have a variety of corals, mostly soft and LPS, but just recently added some SPS frags as well as a derasa clam. I'm also seeing lots of coraline spots showing up on the overflow and rock work.

Prior to the reasoning for my thread, my water was typically 9.7-9.9 Alk/ 490 Cal/ 1440 Mag for my weekly tests. However, since the new additions, I have been going through Alk and Mag at an increased rate. Test kits are Salifert and expire in 2023. I have been double testing recently to confirm my readings. This doesn't seem to be what I'm seeing as the normal conditions for needing 2 Part dosing additives though (alk AND cal being used and needing supplementing)? What could be going on? Should I start dosing Alk only ?


I did a water change on Sept 8 to try and stop the falling trend of Alk (see the spike) and tested water about 4 hours afterwards. This was not my normal weekend to change water, and I can't keep doing changes at what looks like every 3 days?

 

[Hemmdog]

Dose alk only, let the others naturally fall, they are a little elevated.

 

[Phyber]

So nothing crazy going on at this point? I ordered the BRS 2 Part starter kit, but don't want to go wild adding things for no reason... I just need to calculate the daily bump my tank needs to maintain Alk only?

 

[jaxredsoxfan]

I think most folks measure 2 part by the alk demand - not the Ca. As long as that keeps you in the ballpark for both then you're good. I had a similar situation but with low Ca and high ALK. I dosed 2 part at slightly lower than i needed for 2 weeks and finally the levels of both stabilized.

 

[Phyber]

I think most folks measure 2 part by the alk demand - not the Ca. As long as that keeps you in the ballpark for both then you're good. I had a similar situation but with low Ca and high ALK. I dosed 2 part at slightly lower than i needed for 2 weeks and finally the levels of both stabilized.

Ok, so just dose alk, no need to do the equal parts of alk and Cal?

 

[Crossfire]

Dose alk only, let the others naturally fall, they are a little elevated.

Not a good idea. If you dose only alk your calcium will fall fast. Buy any brand of 2 part (calcium and alkalinity) and dose equally. They will balance out over time- usually a few weeks or months. Your levels are fine as long as they are stable. Monitor both calcium and alk every few days to make sure everything is okay.

Your magnesium at 1380 is great. Try to keep it stable around there. If you notice it keeps dropping, just dose it to keep it around that 1300-1400 mark.

 

[BeejReef]

I was about to start my own thread on this, so consider this a BUMP. Near exact same situation as OP. Kalkwasser (equal parts Alk and Calc). Daily demand on 6mo tank was about .9dkh. All was good. Last few weeks, seeing alk demand significantly outstripping Calc. Last night, alk 6.7, calc 440, mag 1400. I target 9.5dkh and about 420 calc. Added a few sps frags, added some dry rubble rock to sump. Both a few weeks back.

ty

 

[Phyber]

I was about to start my own thread on this, so consider this a BUMP. Near exact same situation as OP. Kalkwasser (equal parts Alk and Calc). Daily demand on 6mo tank was about .9dkh. All was good. Last few weeks, seeing alk demand significantly outstripping Calc. Last night, alk 6.7, calc 440, mag 1400. I target 9.5dkh and about 420 calc. Added a few sps frags, added some dry rubble rock to sump. Both a few weeks back.

ty

It seems the debate of "dose 2 part equally" and "dose individual items" is as heated as politics... I have no experience at all with dosing so I'm clueless (never even tested alk/cal/mag before on my first tank) but my logic says that adding something I don't really need (ex. dosing cal despite me already being at 490 cal) doesn't make sense... But others will say if I only dose Alk, my cal will start falling quick which I wouldn't want. So idk.

At current it looks like I would daily dose 18ml of alk to maintain...if that's correct and I also dose 18ml of cal, it wouldn't raise the cal enough for my test kit to notice a .005 ppm difference so I guess it doesn't matter?

 

[BeejReef]

2 part trouble

So I have been at this for about two years and I have always used seachem reef fusion 2part. My skills and reef systems have expanded since then. I now am at the point that I am growing acros successfully. But I am stumped on what to do next. I am constantly running into an issue with...

www.reef2reef.com

Ty, see the above (if you haven't already).

I hate it when I stumble on a controversial topic.. lol. Your question can be met by crickets, or an absolute outpouring of strongly held opinions.. lol. That's how we learn though

I've also read that high calcium can "suppress" alkalinity. Again, no idea if that's true. I'm hoping that's the case.
My working theory is that the tank is demanding marginally more alk than calc and I didn't notice the imbalance before dosing calc high enough to observe the "suppression effect."

If that's not it, I'm stuck with a young mixed reef inexplicably demanding alk like an established sps system... on the order of 1.5dkh per day. Hijack over. You're free to depart

I'm going solo alk iso balance. Will pop in to share my results w u.

 

[BeejReef]

K, so started dosing Randy Alkalinity Recipe Two. Alkalinity up as follows over 4 days. 6.9, 7.8, 8.5, 9.1, 9.8. Calcium fell 450 to 420. Was dosing Alk @ 2dkh per day. Back to balanced dosing. Will see if alk demand is truly higher for me.

How did u make out?

 

[melanotaenia]

Ideally if you don't know what your tank is consuming it is best to test daily for two weeks to see if your dosing stabilizes during that time; it is never a good idea to dose 2-part in equal amounts without testing your parameters first.

Every tank consumes the three chemicals differently; that said, after a couple weeks of daily testing one should be able to have a dosage that can be kept consistent unless major changes to the tank are made.

I would try to keep Alk in the 7-8 DKH range. Calcium at 420 is perfect.

 

[Randy Holmes-Farley]

75g total water volume tank is about 5 months old, and I've been religious with a bi weekly water changes of 20 gallons of Reef Crystals mixed to 1.026.

I have a variety of corals, mostly soft and LPS, but just recently added some SPS frags as well as a derasa clam. I'm also seeing lots of coraline spots showing up on the overflow and rock work.

Prior to the reasoning for my thread, my water was typically 9.7-9.9 Alk/ 490 Cal/ 1440 Mag for my weekly tests. However, since the new additions, I have been going through Alk and Mag at an increased rate. Test kits are Salifert and expire in 2023. I have been double testing recently to confirm my readings. This doesn't seem to be what I'm seeing as the normal conditions for needing 2 Part dosing additives though (alk AND cal being used and needing supplementing)? What could be going on? Should I start dosing Alk only ?


I did a water change on Sept 8 to try and stop the falling trend of Alk (see the spike) and tested water about 4 hours afterwards. This was not my normal weekend to change water, and I can't keep doing changes at what looks like every 3 days?

Magnesium consumption is very slow and is not going to be more than about 1/10th of the calcium consumption rate. Any changes a lot larger are test error, or are from salinity fluctuations.

 

[Randy Holmes-Farley]

2 part trouble

So I have been at this for about two years and I have always used seachem reef fusion 2part. My skills and reef systems have expanded since then. I now am at the point that I am growing acros successfully. But I am stumped on what to do next. I am constantly running into an issue with...

www.reef2reef.com

Ty, see the above (if you haven't already).

I hate it when I stumble on a controversial topic.. lol. Your question can be met by crickets, or an absolute outpouring of strongly held opinions.. lol. That's how we learn though

I've also read that high calcium can "suppress" alkalinity. Again, no idea if that's true. I'm hoping that's the case.
My working theory is that the tank is demanding marginally more alk than calc and I didn't notice the imbalance before dosing calc high enough to observe the "suppression effect."

If that's not it, I'm stuck with a young mixed reef inexplicably demanding alk like an established sps system... on the order of 1.5dkh per day. Hijack over. You're free to depart

I'm going solo alk iso balance. Will pop in to share my results w u.

High calcium cannot ever cause alkalinity consumption without calcium consumption, since they are consumed together, about 1 meq/l (2.8 dKH) of alkalinity consumed along with 18-20 ppm calcium (and maybe 1 ppm magnesium).

 

[Randy Holmes-Farley]

I was about to start my own thread on this, so consider this a BUMP. Near exact same situation as OP. Kalkwasser (equal parts Alk and Calc). Daily demand on 6mo tank was about .9dkh. All was good. Last few weeks, seeing alk demand significantly outstripping Calc. Last night, alk 6.7, calc 440, mag 1400. I target 9.5dkh and about 420 calc. Added a few sps frags, added some dry rubble rock to sump. Both a few weeks back.

ty

You just need more of both calcium and alkalinity dosing in the right proportion. Alk shows depletion well befor calcium kits can observe a clear decline.

 

[Mortie31]

Before you do anything check the levels in your fresh salt mix and make sure the salinity is spot on, if your water change levels don’t match your tank levels you will be forever chasing your tail.