Critique my parameters (Mg dropping?)

[LgTas]

6 month old mixed reef tank (SPS is chili monti, pink birdsnest, and Pocillopora so fairly hardy). 18 % weekly water changes. High Cal in the early days was a dosing mishap. I don't run a skimmer so phosphate management is a bit tricky but on the right trajectory. Magnesium is a bit of a concern as the last two tests (which I did twice each time to confirm) are showing Mag at 1200 and 1175. I have read that Mag tests have a fair bit of error in them so will only panic if the trend continues. All corals looking healthy and growing. Was dosing AB+ but had a big GHA outbreak so stopped that a few weeks back. GHA growth has reduced significantly since then.

All tests bar phosphates (Hanna HI774) are Salifert

NSW parameters (test every third water change. Stay pretty much the same)

Trend graphs:

Any potential red flags? Ideas on the Mg change?

 

[Daniel92481]

Looking good. Get some nitrates in there. I like to shoot for about 2-5ppm.

 

[LgTas]

Looking good. Get some nitrates in there. I like to shoot for about 2-5ppm.

Thanks! graph isn't clear. Nitrates currently at 4 ppm.

 

[Daniel92481]

Thanks! graph isn't clear. Nitrates currently at 4 ppm.

Sounds like some pretty good numbers then!

 

[KrispyKashew]

Looks pretty good to me. I had a large consumption of mag at 5 months when coraline started going crazy. it stabilized quickly after it covered nearly everything.

 

[Randy Holmes-Farley Verified Community Expert]

The magnesium drop is testing noise primarily. IT CANNOT drop by more than about 1-2 ppm per day, and that is only if the consumption of alk and calcium is high. Magnesium consumption is about 1/10th of the calcium consumption, at most.

 

[Cerberusfish]

Everything looks good to me. Alk is awesome. I'd personally like to see the calcium get a bit more stability, but overall it doesn't look terrible and I'm sure that as time goes on the data will get more clear. A lot of the magnesium like others have said is just inaccurate technology in the test kits. If it continues with that downtrend just dose a little bit of magnesium. I like to keep it simple and use a calcium supplement that already had magnesium in it (seachem reef fusion) and so far haven't had any issues.

 

[LgTas]

The magnesium drop is testing noise primarily. IT CANNOT drop by more than about 1-2 ppm per day, and that is only if the consumption of alk and calcium is high. Magnesium consumption is about 1/10th of the calcium consumption, at most.

You were correct. Checked my mag test and the syringe tip had been compressed and was drawing less air and more liquid. Tested today with another and was at 1320.

 

[Randy Holmes-Farley Verified Community Expert]

You were correct. Checked my mag test and the syringe tip had been compressed and was drawing less air and more liquid. Tested today with another and was at 1320.

Sounds good.

Happy Reefing.