MG too high.

Salifert only measures up to 1500ish.
Elos was showing 1700. So I did a water change with reef crystals and it went up too 1800. Probably just a fluke with the test but still too high. How can I lower mag. Otherwise?

Corals have lost color since I put them in my 20 gallon. Except for my goniopora they seem ok. Definetely harder to balance a small aquarium.

 

From what I've readreef crystals average 1300ish freshly mixed.

 

What is dKH, Ca at??? I would just let the tank consume it over time if the other parameters are in check.

 

As I have stated numerous times in this forum, water changes to adjust parameters or to attempt a cure for something is ill advised. Your Mag is high and you did a water change with a salt mix with 1300s ppm of Mag and added that to your already high Mag. If cal is in a range of 400-450 ppm let's say, your mag should be at 1200-1350 ppm. I would have LFS check a sample for you just to be sure your testing is correct, otherwise, you should raise the Cal to be in the correct ratio with the Mag and then let the tank consume the Mag and balance out to where you want the parameters. Keep an eye on PH and Alk in the process.

 

I would question your test kit or test procedure as well, but AFAIK there are no known detrimental effects to having your magnesium a little high. I keep mine right around 1500 most of the time although it goes up to 1550-1600 sometimes and feel like it hasn't done anything negative to my tanks.

If your tank is really at 1700 and you do a water change with 1300 mg level it should have come down some. There is no way it should have gone up except due to an error of some sort. It's basic dilution.

I would personally just let it come down naturally as well as having your water doublechecked by someone else with another test kit.

 

Yeah, thanks,
I'm not necessarily doing water changes to adjust my params normally. Logic would reason if the mix has 1300ppm MG and the tank is 1700 it should come down with a water change. So maybe my testing is bad.
I have two test kits. .. a Salifert and a brand new Elos.

As far as the Ca, and dKH it's all over the place right now as this is a 20 Gallon temporary tank loaded with stonies, and I can't be there everyday to keep things proper. The dkH is usually 8-11 swings a lot and the Ca is around 400 but sometimes comes down to 300 if I'm gone for several days.
Yes, I know not good but until I get a permanent tank set back up It's all I can do.
The Ca and dKH fall like expected but the Mg Is just staying way up there. I haven't been adding any.
I'm in the process of moving so It's killing me.

 

I wouldn't worry too much about high Mg, it's not really harmful, even at very high levels. I would let your tank use it up. Corals can actually use it in place of Ca to grow with when your Ca levels are down. Keep you Ca and dKH in check and you should be fine. THe lose of color is probably from something else, probably lighting or placement.

 

Yeah , the lights are 4 X 24 W T5s on a 20 Gallon.
They're brand new retros. For flow I have a K2 and smaller 200GPH rio power head for 800 GPH.
I've always heard that GSP won't open when the Mg is too high but it is still opening.
It's frustrating trying to keep this tank up cuz I don't have it as automated as my main tank was.
Gonna have to move it cross country soon.

 

Really much ado about nothing 1700 ppm Mag will do no harm or no good . I have jacked Mag levels to 4,000 plus PPm and never lost a thing .Not even the bryopsis it was supposed to kill out. Just allow it time to get back in line and as Otty asked the ca and buffer can play a role in the levels at 1700.

 

Ok, cool thanks everyone.