Water changes and trace elements

[Capsle]

Morning reefers,

This might be a chemistry question but if it is its in the beginners field.

So I do about a 12% water change every other week. Changing about 10g for an approximate 80g system.

My water has always been stable and still is. I'm slowly increasing salinity and Mg. dosing Mg every other day to get it to 1385 and test Mg the day after I dose.

My question is should my Ca be going up when I do a water change? Here are my parameters before WC (tested Sept 4) and after (tested Today Sept 7)

Before
Salinity 1.023
PH8.0
Nitrites 0
Ammonia 0
Nitrates 5-10
Cal 430
Alk 9.3
Mg 1290
PO4 <0.03

After
salinity 1.024
PH 8.0
Nitrites and ammonia 0
Nitrates 5-10
Cal 430
Mg 1320
Alk 10.0
PO4 <0.03

Cal stayed the same while Alk went up and Mg as well (Mg I dosed the day of WC so normal). Alk is in range with my Salt Ca as well.

Should my Ca be going up or is it normal for it to be the same?




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[scooter31707]

Do you have any coralline algae or corals in the tank? If so, that could be why.

 

[daplatapus]

Have you tested your water change water? Some salts like Instant ocean can vary quite significantly from batch to batch and have an affect on your overall water parameters after a change.

 

[Capsle]

Do you have any coralline algae or corals in the tank? If so, that could be why.

I have a small hammer frag about the size of a quarter, a torch, small zoa frag and yes coarline algae is growing on the rocks.

 

[Capsle]

Have you tested your water change water? Some salts like Instant ocean can vary quite significantly from batch to batch and have an affect on your overall water parameters after a change.

For Salt I am using Red sea coral pro, and fresh SW is withing those ranges.

 

[thegrun]

Since you are only making relatively small water changes it is unlikely you will see much inn the way of any jump in calcium. For example if you did a 15% water change with water at 460ppm ca in a tank with 420 ca your calcium would only increase to 426. 6 ppm could easily be consumed by coraline algae, stony corals or calcium precipitation. 6ppm is also well within the limitations of our hobby test kits so even the 6 ppm might not show up in your testing results.

 

[BlackTip]

Since you are only making relatively small water changes it is unlikely you will see much inn the way of any jump in calcium. For example if you did a 15% water change with water at 460ppm ca in a tank with 420 ca your calcium would only increase to 426. 6 ppm could easily be consumed by coraline algae, stony corals or calcium precipitation. 6ppm is also well within the limitations of our hobby test kits so even the 6 ppm might not show up in your testing results.

+1
If it is not consumed, it is within the margin of error.