Mg constantly at 1500

[Koh23]

Ok, i know that this is impossible....

But, my mg levels are at 1500 whole time. I don't dose mg, i don't do water changes often (maybe every 3-4 months maybe 5-10%).....

I dose calcium and alk (tropic marin advanced ca and soda for alk).

Other than that, few drops of amino acids lately.

Tank is 500l, everything is doing great, so really no worries here, but, i'm wondering....

Beside logical conclusion that test kit (aquaforest mg) is bad and readings are wrong, i wonder, is there any other possible reason that tank dont use mg?

Edit - ca and alk usage are normal, i dose cca 90ml of ca and 90ml of alk, for keeping ca at 450 and alk at 11.

 

[Doctorgori]

I’d go ahead and cop a Salifert Mg anyway …
$20 and in 2-3 days might be worth the piece of mind
…can’t hurt

 

[Randy Holmes-Farley Verified Community Expert]

It’s either test error (very common) or a very high magnesium salt mix. Consumption will not likely reduce it noticeably ad Mg demand is always very low.

 

[Daenion]

It’s either test error (very common) or a very high magnesium salt mix. Consumption will not likely reduce it noticeably ad Mg demand is always very low.

Randy a quick question if you got time on that subject.

My mg goes down by almost 50-60 in a week. I only dose every couple weeks but upped it to weekly now. Do you think this is due to coralline? My tank net water is about 130ish gallons.

 

[Randy Holmes-Farley Verified Community Expert]

Randy a quick question if you got time on that subject.

My mg goes down by almost 50-60 in a week. I only dose every couple weeks but upped it to weekly now. Do you think this is due to coralline? My tank net water is about 130ish gallons.

It is likely either a salinity change or test error. Demand for magnesium is not more than 1/10th of the calcium demand. So unless your calcium demand is 500-600 ppm in a week (which would indicate excessive precipitation).

 

[Lavey29]

1500 won't hurt anything but slightly lower would be more beneficial long term.

 

[Stephen8169301]

My salt mix is also 1500mg in its IO reef crystals

 

[Koh23]

Salt, that i dont use often, is af sea salt, so mg levels shpuld be around 1350 in fresh mix.

Since i dont dose, all goes back to faulty test.

 

[bushdoc]

Had same situation. Love Aquaforest tests, but their Mg test seem to give repeated high value, even if you strickly adhere to testing protocol.
I switched to Salifert and all of the sudden my Mg is 1350.

 

[Koh23]

Agree, i asked mainly because maybe there is "something" that may affect othervise correct test, food, anything that can confuse test to give false readings.

I guess ill try salifert, or anything else.

Thank you all!

 

[Koh23]

Ok, so i tested with hanna tester, and it shows mg level of 1415.

So i guess nothing is wrong with my test kit, this is one, maybe two drops more, or i simply dont see color change at right drop.

But now, question is, is it possible that tank dont consume mg? I mean, i dont dose it, i dont do water change.... And in no way i sumplement magnesium, that i'm aware of.....

 

[Randy Holmes-Farley Verified Community Expert]

Ok, so i tested with hanna tester, and it shows mg level of 1415.

So i guess nothing is wrong with my test kit, this is one, maybe two drops more, or i simply dont see color change at right drop.

But now, question is, is it possible that tank dont consume mg? I mean, i dont dose it, i dont do water change.... And in no way i sumplement magnesium, that i'm aware of.....

If I were you, I'd jsut stop measuring it. it is fine and will be for a long time.

As mentioned, magnesium consumption is very low. So low that for most people, I don't reven recommend measuring it as, in a case like this, it causes more angst than it is worth.

It never depletes faster than about 1/10th of the calcium depletion rate.

 

[Koh23]

Thank you.

Calcium is depleted, well, i cannot say is it fast or slow, but, i dose 100ml of calcium daily, same as kh.

I guess that best thing to do is simply stop testing for some time.....

 

[Randy Holmes-Farley Verified Community Expert]

Thank you.

Calcium is depleted, well, i cannot say is it fast or slow, but, i dose 100ml of calcium daily, same as kh.

I guess that best thing to do is simply stop testing for some time.....

Assuming that is a typical two part, (such as my DIY recipe #1 (BRS uses this), that 100 ml per day in 500 L is a calcium addition of 8 ppm per day. Thus, magnesium depletion is less than 1 ppm per day, and water changes will help offset that decline.

 

[Koh23]

Really not sure, now i use tropic advanced calcium, mixed per instructions, 55g on 1l rodi water.

How potent is that solution really dont know, ill switch to something more reliable as soon as possible, but primary i need to get me hanna checker, test kits are too much for my eyes to determine consumption more precisely....