Magnesium too high, all the time.

kinetic · Jan 11, 2018

Salt: Aquaforest Reef Salt
Water Changes: 10% weekly
Test Kit: Red Sea Pro kit's mg test

I follow the directions exactly. Though here is what I do as a review:
1. 2ml of tank water
2. 1x drop of A. Shake for 15 seconds. Repeat 5x for a total of 5 drops.
3. Add 5x drops of B. Shake for a minute.
4. 1ml of the titration liquid
5. I push about 7ml through to start, swirl for 15 seconds, then slowly add drop by drop, swirling between each drop until it turns blue. I always get down to 8.4ml of titration used. This is over the 1600ml max that this test kit tests for

I dose AquaForest component 1+, 2+ at 17ml a day, but never dose 3+ since my mg is always so high. It's been about 4 months.

Alk: 8
Ca: 420
Salinity: 1.026

I know red sea test kits read high, but usually not THIS high. The last time I tested was 1 month ago, and it was also 1600ppm.

I'll try to use someone else's test kit this weekend, but let's assume this is still too high, should I reduce magnesium by finding a salt mix with very low magnesium? I'm guessing I should also test my newly mixed batch of water next water change to check if the levels are super high? Any other AquaForest Reef Salt users have this issue?

Hitman · Jan 11, 2018

I’ve never had a Red Sea MG test be accurate. I now use Salifert test kits and find them spot on for mg, Ca, and Alk. Try taking a water sample to your lfs and have them test it to see if you have a bad test kit.

chromis · Jan 11, 2018

Do you want to maybe edit your test recipe - I’m guessing you meant that you add a total of 0.84ml not 8.4ml? Try watering your sample down and seeing if the Mg level is indeed lower as a sanity check? Check your test kit expiration date? Check if your additives contain Mg (some alk and Ca additives do) then you might switch to ones that don’t contain extra Mg? Maybe it’s real, if your salinity is so high?

kinetic · Jan 11, 2018

chromis said:
Do you want to maybe edit your test recipe - I’m guessing you meant that you add a total of 0.84ml not 8.4ml? Try watering your sample down and seeing if the Mg level is indeed lower as a sanity check? Check your test kit expiration date? Check if your additives contain Mg (some alk and Ca additives do) then you might switch to ones that don’t contain extra Mg? Maybe it’s real, if your salinity is so high?

Yeah, calibrated my refractometer so my salinity is spot on. When I tested the Alk in my newly mixed water it was right around 8dKH, so that was a good sign.

I'll check my additives and other things. Thank you!

Randy Holmes-Farley · Jan 12, 2018

kinetic said:
I'll try to use someone else's test kit this weekend, but let's assume this is still too high, should I reduce magnesium by finding a salt mix with very low magnesium? I'm guessing I should also test my newly mixed batch of water next water change to check if the levels are super high? Any other AquaForest Reef Salt users have this issue?

I don't think there is a salt mix with very low magnesium. But a water change with a normal mix would help if magnesium really is high.

You should be able to calculate the exact magnesium value from the amount needed to get to the endpoint. If it is "off the chart", get the value from lower amounts. For example, if it is 8.4 mL, look up the value for 4.2 mL and double it.

kinetic · Jan 12, 2018

Just tested a new batch of water with the Aquaforest Reef Salt. I used 0.9ml of titration this time. That's even more than my display (which makes sense, my corals must be using a little bit of it).

.45ml used is 900ppm, so I guess the salt mix is mixing at 1800ppm. Bummer, as I have 3 full buckets of this stuff still.

Randy Holmes-Farley · Jan 12, 2018

Hopefully it’s the kit that is off.

subnet88 · Jan 15, 2018

I was just about to post a similar question. My AF reef salt is mixing at 1700ppm @ 35ppt salinity. @Randy Holmes-Farley What is the negative of magnesium that high?

subnet88 · Jan 15, 2018

Duplicate

subnet88 · Jan 15, 2018

Duplicate

kinetic · Jan 15, 2018

I'm still waiting for my Salifert kit to be delivered. Hopefully this week!

Randy Holmes-Farley · Jan 15, 2018

subnet88 said:
I was just about to post a similar question. My AF reef salt is mixing at 1700ppm @ 35ppt salinity. @Randy Holmes-Farley What is the negative of magnesium that high?

It’s hard to know for sure because most often people get there by large doses of a supplement, and effects may be from impurities in the supplement. But lethargic snails is commonly reported.

kinetic · Jan 15, 2018

Randy Holmes-Farley said:
It’s hard to know for sure because most often people get there by large doses of a supplement, and effects may be from impurities in the supplement. But lethargic snails is commonly reported.

Interesting. My snails are REALLY lethargic. I've had snails in other systems before so I can definitely tell. I've been worried they were all dying, but they have been alive and well for 3+ months in this state... Not sure if it's related.

subnet88 · Jan 15, 2018

Randy Holmes-Farley said:
It’s hard to know for sure because most often people get there by large doses of a supplement, and effects may be from impurities in the supplement. But lethargic snails is commonly reported.

Are there any reported issues with calcification or coral mortality with high magnesium?

Randy Holmes-Farley · Jan 15, 2018

subnet88 said:
Are there any reported issues with calcification or coral mortality with high magnesium?

Im not aware of any, but that doesn’t mean it can’t happen.

Dukeap · Jan 16, 2018

Hi, i have been using skinz pro reef salt that also mixes high on mg not as high as you guys but in the high 1400 to 1500. I testing with the reds sea mag test kit and was getting 1440 to 1580 after researching on here i realized those test kit read high and i went out and got the salizer test kit and its now reading 1350 test again and got the same thing, different test kit will give you the correct number

jml1149 · Mar 15, 2018

I just found this thread. Tested with a brand new Salifert test kit, Mg at 1710!! Oye! Seems like its not too big of a deal, I do notice some reduced PE in one coral, and lethargic snail may be an oxymoron, but I believe I see it here too.

jml1149 · Mar 15, 2018

Aside from water changes, is it worth trying to lower? I don't know where 1710 comes from, I only dose Kalk.

reeferdon · Mar 15, 2018

WOW
I'm having the problem. High Mag with Aqua Forest Reef Salt. Not sure what to do.
I'm using the AF Mag Test Kit. That being said, I use my test kit on my friends tank and get normal reading.

Randy Holmes-Farley · Mar 15, 2018

If you think the test results are correct (they often are not), I might switch to a lower magnesium salt mix for a while. That’s the only thing one can do about high magnesium, besides ignoring it.

The River · May 28, 2018

I am really struggling in the same boat... AF reef salt, dosing components 123 minus 3 because of mag issue... On a doser. Red sea test kit reads 1620 to 1640 ish. Did a 20 percent water change today with Instant Ocean Salt (not reef) and still have mag at 1600... Really looking for some advice. Cant get my magnesium down