RSCP and High Magnesium

pdiehm · Dec 10, 2015

I have been doing weekly 5g changes in my biocube 29 on my water change day...just force of habit.

My Mg test results since I started using Aquarimate:

7/10: 1600
7/23: 1440
7/30: 1540
8/20: 1420
8/27: 1550
9/4: 1600
9/18: 1600
9/28: 1600
10/4: 1560
10/10: 1600
10/31: 1400
11/22: 1600
11/29: 1560
12/7: 1540

My Ca tests in same time frame:

500
450
450
450
435
450
470
450
440
440
400
445
425
400

Alk:

9
10.1
9.5
10
10
10.6
10.6
9.8
9.2
9.5
9.8
10.9
10.7
9.8
9.5

Is this something I need to worry about? Calcium and Alk appear to be fairly consistent, and the test kit I am using is the Red Sea Reef Foundation Pro kit.

Having said that, when I switched to RSCP, I had a slight hair algae problem, and within a month of doing 2 5g changes per week, and the high Mg, the algae problem disappeared.

Randy Holmes-Farley · Dec 10, 2015

The magnesium bounces are just testing error, which is not uncommon. It does not move around that fast unless you do huge water chasnges with off mixes, or are adding huge amounts at once.

What kit are you using?

What salinity?

Are you dosing anything?

The Red Sea Coral Pro claims to have about 1475 ppm at 35 ppt (sg = 1.0264).

pdiehm · Dec 10, 2015

Salinity is 33-34 on average.

Test kit is Red Sea Reef foundation pro kit

Downbeach · Dec 10, 2015

I'd get a second opinion on the Mg kit. Some variations can be expected. Are these readings done after WC's? Whats your SG?

pdiehm · Dec 10, 2015

Downbeach said:
I'd get a second opinion on the Mg kit. Some variations can be expected. Are these readings done after WC's? Whats your SG?

The tests are done a day before my change.

What I am doing is mixing the salt for 30 minutes. I may try mixing it for 3 hours tomorrow and see if that makes a difference

pdiehm · Dec 10, 2015

And no dosing Randy. I am finding that I can maintain stable Ca and Alk with the weekly water changes

pdiehm · Dec 10, 2015

Maybe I am doing too much? Cut it in half which would be closer to the 10% (est system volume is about 23 gallons)

Downbeach · Dec 10, 2015

I would do both, mixing it longer, and do smaller more frequent WC's(if necessary). I would also mix up your salt mix when you open it to ensure there wasn't any elemental stratification that may have occurred during shipping. For improved consistancy, I'd get your SG to 1.026(35ppt) using a properly calibrated device, i.e. refractometer using a 35ppt calibration solution.