Low magnesium

[Susan Edwards]

For some reason, I'm battling low magnesium in my 60 gal tank. I've always had to dose 30 mil or so. I went to a dosing pump and the tubing was out for a couple days (it flipped up). Since then, it's been in the 1100's-1200's. I also changed from Red Sea test kit to salifert. I didn't used to have an issue maintaining around 1300.

I am dosing 4x's day up to 13 ml each dose. And I've been adding another 10 ml or so manually though not every day as I forget. Today it is at 1260. That was adding almost 20 ml extra yesterday. Is this normal to have to dose so heavily? I also did a 8% water change yeterday.

Ca is 420
Alk is 8.3

Those 2 are holding very steady. If I don't add extra mg to what I am dosing, it falls into the 1100's. Previous to auto dosing, I was dosing around 30-35 if it was low, or 4-15 if it was in range. Should I stop auto dosing and go back to manual until I get it up to around 1350, get it steady and then retry auto dosing? I just posted another post on my nitrates so there is all my tank info in that post.

 

[sde1500]

Just read your other post, so I remember the details, but its usually a good suggestion to give all your details in the current post. Don't make people that want to help go find another post you made to learn what you have. What are you doing for MG? Quick run of the numbers of the BRS website, using their calculator and picking their MG mix, to go from 1280 to the target of 1350 you need to dose 338.7 ML. So your 13ml 4x a day is doing pretty much diddly squat.
https://www.bulkreefsupply.com/reef-calculator

 

[Susan Edwards]

Good point @sde1500 so here are the tank particulars. I should paste it into a word file.... What I've been doing for the mg, using esv brand, is adding extra to the dosage amt, usually 10-20 a day as I figure getting up to 1300 slowly is better than 300 ml overnight. I'll up what I add a bit more today and retest tomorrow. Once I can get it to where I want, I'm hoping what I'm dosing will keep it there. If I have to dos over 300 each day, something is wrong somewhere. I'm using the salifert test. RS before that so maybe RS was way to low all this time.

Red Sea Max C250 (approx 60 gal water after rock and sand)
2 chromis, 2 mandarins, 1 scooter blenny
2 Darwin clowns, 1 barber shop goby will be moved from QT to DT on Friday
Tank just over 11 months old
4-5 narsarius
2 bumble bees
Trochus--too many to count as they breed like rabbits
3-4 hermits
1 rbta that is on it's way out. Still alive so not the problem though I may remove the rock it's on and put it into my coral QT

CA 420
Mg 1260 (subject for another post as I cannot get this up)
Alk 8.3
PO4 .02
NO3 80 usually between 20-40 with occasional spikes to 80

Feeding:
fish 2x's a day
corals every 2-3 days a mix of various dry powders
Suns every other day or so, along with corals that appreciate meaty foods
Adding phytoplankton every day for nutrient control and pods

 

[sde1500]

I doubt you'd need 300ml a day. But you let it get too low and need to bring it up to balance everything. 100p point swing in a day isn't too terrible. Side note, I occasionally feed my tank phytoplankton too, but what do you mean by nutrient control? You won't get it to lower nutrient levels with phyto if that's the idea.

 

[johnnyk731]

So I too have low mg and per the EVS gallon jug of MG it says 1.5 ml to every gallon to raise it 15 ppm per day I’m dosing 210 a day to a rsr 525xl which is 139 gallons but I’m accounting for sand rock and sump equipment displacement and it goes up everyday at a steady pace. I started at 1080 two weeks ago now I’m into the 1200s so for 60 gallons I’d get a decent estimate of the actual water amount and multiply that by 1.5 and add that number in ml per day until goal is reached then test every other day to see what a maintaining dosage should be also note that adding mg will prob decrease alk so be sure to keep that in check at the same time. ... just my two cents

 

[Ubergroover]

check out aquaforest component +1 +2 +3...I dose 50-20 ML daily in a 75G DT. Ca is 460 steady, Mg is 1350 steady, Dk is 8 steady. I use their probiotic reef salt for a partial WC once a month. That's only out of habit. I test twice a week. parameters never change. I really do not even need to do water changes. ....stuff works.

 

[rkpetersen]

I've found that manually dosing 30 ml/100gal/day of Brightwell Magnesion for a few days will increase my magnesium quite predictably, about 8-10 ppm per day, if it starts to drift low despite 2 part dosing. No adverse effects noted from dosing this once a day into the overflow. Very important to shake this product well before using it, every time.