Is this normal? Alk lower and Ca gettin Higher?

[Timrpn]

Hi,
I have not dosed anything or done any water changes. I just moved and setup, combined this new tank 5 days go.

Day 3: Alk 10.8 Ca 479
Day 4: Alk 10.6 Ca 476
Day 5: Alk 10.4 Ca 487
Mg 1320 All 3 days

 

[Timrpn]

Hi,
I have not dosed anything or done any water changes. I just moved and setup, combined this new tank 5 days go.

Day 3: Alk 10.8 Ca 479
Day 4: Alk 10.6 Ca 476
Day 5: Alk 10.4 Ca 487
Mg 1320 All 3 days

Should Add that I am using Hanna Checkers for Alk and Ca

 

[nereefpat]

Looks very normal to me.

The alk is very slowly dropping at a rate of 0.2 dKH per day.

The Ca isn't really going up. The few ppm difference is just the standard error from you and the method.

FYI, using the ratio of alk: Ca consumption, a drop 0.2 dKH would typically equate to a Ca drop of about 1.4 ppm, which isn't measurable by our instruments.

 

[saltyfilmfolks]

^^^yup.

 

[chipmunkofdoom2]

It's worth noting that because of the dilution required, the Calcium Checker from Hanna is not the most accurate. It's likely close enough, but I would treat the results as "close" and not "exact."

 

[Randy Holmes-Farley Verified Community Expert]

The calcium rise is likely just noise in testing.

 

[Timrpn]

So, I should not be concerned.

Tested just now: Alk 10.2. Declining by 0.2 DKH daily
Calcium just tested 506

 

[Geebs19]

Margin for error on the calcium is +- 6%. How do you clean the vials?

 

[Timrpn]

Just rinse under tap water

 

[Geebs19]

Just rinse under tap water

You might be getting calcium build up within the vial without knowing about it/seeing it. Could be throwing off your numbers.

 

[Timrpn]

How do I clean properly? The 506 reading was in a new vial from the Hana test kit, I just got it last week.

 

[Tft12]

How do I clean properly? The 506 reading was in a new vial from the Hana test kit, I just got it last week.

I wash with a bottle brush in tap water and then always do a final rinse with DI water for all testing equipment.

 

[Randy Holmes-Farley Verified Community Expert]

So, I should not be concerned.

Tested just now: Alk 10.2. Declining by 0.2 DKH daily
Calcium just tested 506

Correct. Nothing unusual or concerning.

 

[Timrpn]

Ok with my Alk declining at .2 daily what would you suggest I keep it at? Let it fall a bit more or keep where it is not. Increase?

 

[Randy Holmes-Farley Verified Community Expert]

Ok with my Alk declining at .2 daily what would you suggest I keep it at? Let it fall a bit more or keep where it is not. Increase?

IMO, anything between 7 and 11 dKH is typically fine. Higher gives faster hard coral growth if nutrients are adequately high, and lower (7-8 dKH) allows nutrients to be lower without getting burnt SPS tips.