I've been fighting low Mg. Levels and therefore Ca. and Alk. too. I've been running a gfo reactor to reduce phosphorus so I don't get an algae issue in the future. I was wondering if that could be the reason I don't have high Mg.? I use red sea coral pro and switched to that vs. Instant Ocean. Still got 800-900 mg. And un traceable Ca. I even tried raising salinity thinking my refractometer was off. I'm outta ideas. Any help would be greatly appreciated. Tom
GFO reducing Mg.?
- Thread starter 75gal
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Give us your alkalinity and calcium test results. Have you tried dosing Mg? Are you sure you are testing correctly? What brand of tests are you using. Ca should have results even if it is low, which leads me to believe the test results are not correct. You may want to see if your local fish store will run their own tests.
CStrickland
New member
How often, how much do you change the water?
Have you tested the new water before you add it?
The only way I can think of gfo reducing mg is if it got the phosphate low enough to where coralline exploded and sucked up all the mag. I don't think that's your issue, tho. More likely a bad test result, or your mixing it wrong like not shaking up the bags of salt or something like that.
Have you tested the new water before you add it?
The only way I can think of gfo reducing mg is if it got the phosphate low enough to where coralline exploded and sucked up all the mag. I don't think that's your issue, tho. More likely a bad test result, or your mixing it wrong like not shaking up the bags of salt or something like that.
If you are changing out approx. 25-30% of your water every week with RSCP you should have plenty of mag. RSCP freshly mixed is around 1390.
Test your newly mixed salt water and see if it matches what the levels are on the label. If you aren't close, test kit/process are bad.
CStrickland
New member
Yeah, if it comes in the bags you want to shake them up, if it's a bucket you can roll it across the floor, before you scoop out the salt. If the salt has been sitting around in a warehouse for a while the trace bits can settle out.
Also, make sure the kits aren't expired, and you are mixing the salt like the directions on the bag (sometimes people get creative like making really concentrated mixes in one bucket to dilute later etc)
Another option is bringing a sample to a lfs for them to test. They should do basic ones like this for free to double check your kits.
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