Parameters in check?

[jlabeaume]

So I did my biweekly 25% water change using reef crystals. Water before the change shows
PH 7.8
KH 7
Mag 1480
Calcium 420
That was Monday 5/30

So I tested the water yesterday 6/1
PH 7.6
KH 12
Mag 1440
Calcium 470

And again today 6/2
PH 7.8
KH 11.2
Mag 1500
Calcium 380

All tests are rea sea pro. Held at 1.026sg. Checked at each test.
Ammonia, nitrates, amd nitrites all 0.

Does this seem right. Mag goes up? And that much drop in calcium in one day?

 

[heathlindner25]

Sounds like there's some human error in the testing, no way Calcium is going to drop that much

 

[jlabeaume]

Sounds like there's some human error in the testing, no way Calcium is going to drop that much

Very well possible. No denying that. My kids love to "help"

 

[Dogshowgrl]

Test that Kh again. If it really is swinging like that Ca is not going to matter.

Kh needs to be stable. The range they say is huge 7-11. But I find the number my tank will stay stable at without forcing it (mine is 7.2 in one tank and 11.4 in another) and hold it there. I don't dose unless I absolutely have to. It's a pain long term. So find your number and keep testing and maintain. I would make sure I was testing roughly the same time of day. What ever number you find it like you want swing of no more that .4 but a swing of 1 with corals is time to take serious action.

Do the Mg test VERY slowly with RedSea it is very slow to react and will easily give a false high reading. Or that what our RedSea rep says all the time. I think this is why the third test goes up.

Ca just needs a little retesting.

When I test and it seems extreme I test three times and take an average. I work at a LFS and have seen way to many crashes from one bad test and the owners taking drastic action or none at all.

Good luck.

 

[Ron Reefman]

If you haven't already, find a routine for doing your parameter tests. And I mean a routine in the actual doing of the test. Take your time and do every part of the test the same way every time. I'm not saying you are doing it badly, but I have seen people do them quickly and using different techniques every time and therefore get different results. Things like not cleaning the test tubes after they are done, or using their finger to cap the tube rather than the plastic cap (your finger can introduce contaminates).

The exact values you get are only good if you do the test the exact same way every time. And the stability in the levels is just as important as the levels themselves. A dKH of 10 for 6 tests in a row is better than a dKH that is 7 one day and 12 the next time you test. Also consider testing your new saltwater before you do the water change. Maybe even test the tank both before and after the water change so you can see how the new water (that you tested) changes the levels in the tank.