Water changes and trace elements

Capsle · 09/07/2016, 06:37 AM

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?

Sent from my iPhone using Tapatalk

scooter31707 · 09/07/2016, 08:20 AM

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

daplatapus · 09/07/2016, 08:23 AM

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 · 09/07/2016, 09:15 AM

Quote:

Originally Posted by scooter31707

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 · 09/07/2016, 09:16 AM

Quote:

Originally Posted by 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.

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

thegrun · 09/07/2016, 11:38 AM

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 · 09/07/2016, 01:09 PM

Quote:

Originally Posted by 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.

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

09/07/2016, 06:37 AM	#1
Capsle Registered Member Join Date: Jul 2016 Location: Montreal, Quebec, Canada Posts: 385	Water changes and trace elements 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? Sent from my iPhone using Tapatalk __________________ Caps Current Tank Info: 65G DT with custom overflow, 35G custom sump, maxspect R420r 180w 15K, reef octopus classic 150 skimmer.

09/07/2016, 08:23 AM	#3
daplatapus Registered Member Join Date: Jun 2011 Location: Port Alberni, B.C., Canada Posts: 895	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. __________________ 130 lbs Tonga LR, GFO and Carbon reactors, Tunze ozmolator ATO, 2- 20 gal QT tanks, Current Tank Info: 80 gal display 48L X 24H X16D, 2 MP-40's, Odyssea 2-250W MH 4-HO T-5 Actinic's, 80 lbs Aragonite sand, 4 - 150W titanium heaters, Reeflo Baracuda return pump, 150gal sump, Filter Guys Reef Miser 6 stage + 1 Dual RO/DI, LifeReef 48" Skimmer

09/07/2016, 08:20 AM	#2
scooter31707 Registered Member Join Date: Feb 2015 Location: Virginia Posts: 4,971	Do you have any coralline algae or corals in the tank? If so, that could be why.

09/07/2016, 11:38 AM	#6
thegrun Registered Member Join Date: Dec 2008 Location: Garden Grove, Ca Posts: 17,023	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.