THE BIG 3: Where to keep your Cal, Alk and Mag in your reef tank?

BRS

How important are keeping Calcium, Alkalinity & Magnesium numbers consistent for you?

  • All three are important to me

    Votes: 311 53.3%
  • Calcium and Alkalinity are all I really care about

    Votes: 103 17.7%
  • I really just watch my Calcium level

    Votes: 4 0.7%
  • I really just watch my Alkalinity level

    Votes: 145 24.9%
  • Other (please explain)

    Votes: 20 3.4%

  • Total voters
    583

revhtree

Owner Administrator
Review score
+1 /0 /-0
View Badges
Joined
May 8, 2006
Messages
44,182
Reaction score
70,936
Review score
+1 /0 /-0
Let's see where all the cool kids are keeping their BIG THREE levels at these days! Calcium, Alkalinity and Magnesium are often referred to as the BIG THREE and the most important trifecta of numbers that keep are corals healthy, happy and growing. Of course there is more to THAT story but it all starts with the trinity of reefing chemistry. Let's talk about it today!

1. What do the numbers look like for you when it comes to Calcium, Alkalinity and Magnesium? What's your target?

2. How important are these three numbers for you? Do you have a hard time keeping them consistent?



Tang Go's @Thank_Space amazing drop off reef shared via @Aquaforest
Tang-Go.jpg
 

Stoney

Active Member
Review score
+0 /0 /-0
View Badges
Joined
Mar 15, 2019
Messages
180
Reaction score
311
Review score
+0 /0 /-0
I used to test all three weekly but now just Alk twice a week and Ca/Mg once every few months. Ca/Mg just vary so slowly (w/ 10% weekly wc) and have such a wide range of acceptable numbers that the corals dont seem to mind. Ca has settled out to slightly under 400ppm and Mg to 1200ppm.

I really wish auto testers like the trident would focus on Alk, PO4, and maybe NO3. Just seems like a waste to have Ca and Mg on an auto tester when they're so stable.
 

guylaga

Active Member
Review score
+0 /0 /-0
View Badges
Joined
Feb 19, 2021
Messages
277
Reaction score
337
Review score
+0 /0 /-0
Location
Houston
Alk gets tested at least twice a week, so long as that is tracking where I want it I'm happy since I dose Alk and Ca equally.

Will still test Ca and Mg twice a month or so just to make sure they are staying in-range.
 

unchaotic

Well-Known Member
Review score
+0 /0 /-0
View Badges
Joined
Feb 28, 2021
Messages
609
Reaction score
820
Review score
+0 /0 /-0
Location
Minot
Watching Alk like a hawk now. Switched from FOWLR to mixed reef and my kalkwasser dosing was driving everything through the roof for the first two months or so. So I cut back and got relaxed on testing. My Alk plummeted and my Red Dragon acro started bleaching. Might have been ok if I'd have just left it alone but I fragged it and it all died in a few days.
 

elorablue

Valuable Member
Review score
+0 /0 /-0
View Badges
Joined
Jan 5, 2021
Messages
1,762
Reaction score
6,166
Review score
+0 /0 /-0
Location
Ontario
All im concerned about right now are Alkalinity and PH. Test for those every 2 days. Alk kept at 8.7, PH 8.1 (trying to get that up)
calcium and magnesium I couldn't care less about because in my tank they're always around 500 and 1500 and never change, so I test those every 2 weeks or so.
 

NDIrish

Well-Known Member
Review score
+0 /0 /-0
View Badges
Joined
Jun 27, 2019
Messages
539
Reaction score
729
Review score
+0 /0 /-0
Location
Jackson, TN
Ca 420 - 425
Alk 8.5 - 8.8
Mg 1300 - 1350
Ph 7.8 - 8.0 want it to be around 8.3.
Going to make a diy C02 scrubber to ty and bring it up. Did the cup of water outside. It went from 7.81 to 8.19 in an hour.
 
Last edited:

Stv

Active Member
Review score
+0 /0 /-0
View Badges
Joined
Jul 8, 2021
Messages
170
Reaction score
63
Review score
+0 /0 /-0
Location
Santa Clarita
Ca 420 - 425
Alk 8.5 - 8.8
Mg 1300 - 1350
Ph 7.8 - 8.0 want it to be around 8.3.
Going to make a diy C02 scrubber to ty and bring it up. Did the cap of water outside. It went from 7.81 to 8.19 in an hour.
I made one out of a 16oz water bottle and ran the intake off the back for fresh air from my skimmer. It made my ph problems go away permanently. 7.8 for months to 8.2 steady in a week. Everything is showing growth now and 30% livelier.
 
BRS

What do you use?

  • Gfo

    Votes: 4 5.3%
  • Carbon

    Votes: 26 34.2%
  • Carbon & GFO

    Votes: 29 38.2%
  • Water changes

    Votes: 43 56.6%
Top