Magnesium issue in nano tank

[donut0079]

I just got finished testing the water in my bio cube 29 mixed reef and had a pretty sharp drop in magnesium from my last test. I measured the level at 1120ppm. Calcium is at 440. Alk 9 dkh. I measured it using a Red Sea test kit. I was planning on using the bright well mag supplement to bring it up. I was just wondering if anyone could share experience with this product and if the recommended dose for raising mag is appropriate. Thanks in advance.

 

[bertoni]

That supplement should be okay, but I don't know what that company's dosing recommendations are. Up to 100 ppm per day should be safe, although I'd target less for the first doses, to make sure that the water volume estimate is close enough.

 

[donut0079]

They recommended no more than 10 mL per 20 gallons per day

 

[bertoni]

You'll be dosing for a very long time to raise the level with that tiny a dose. I suspect that recommendation is for daily dosing to handle consumption, not for raising the magnesium level.

 

[donut0079]

Yeah that is what I thought and wanted to confirm. The advanced area on the bottle states that it raises 1 gallon by 26 ppm per mL. So I'm thinking I'll target a 50 ppm increase per day over four days or so. I think if I did the math right it's about 43mL per day since my water volume is about 20 gallons.

 

[donut0079]

Oh whoops there was a little math error there looks like 50 ppm is more like 38 or 39 mL

 

[bertoni]

Okay, good luck!

 

[cougareyes]

I use brightwell mg, love it. Roughly you want mg at 3 times your ca, I would dose up to 100ppm a day until you've brought your mg up to 1320 or so. I had about 20 gallons of water volume in my 29g and would dose 80ml to bring up 100 when I didn't keep up with it, did this many times over the years.

 

[bertoni]

As long as the magnesium is at 1275 ppm or so, the tank should be fine. I wouldn't worry about fine-tuning the magnesium level. I ran with magnesium at about 1100 ppm for years with no problems because the old IO came at that level.