magnesium, calcium & alk

[gaker]

I'm kind of struggling to get the calcium/alk/magnesium numbers up in my nano SPS tank.

The tank is pretty new (about 9 months old), so most of the hard corals are fairly small.

I've been dosing Reef Fusion 2 part, and can't get calcium anywhere close to 400. I've also been dosing "advantage magnesium" from seachem, but can't seem to get the mag to go up.

After dosing mag this last night and this morning 3 tsp in water added to the sump, I'm at:

magnesium 1140
dKH 10.2
calcium 380 (this is the highest I've ever had it)

A few hours after dosing, mag was still at 1140.

the display tank is 12 gallons, with a 10 gallon sump. I'm using instant ocean reef crystals and keep salinity at 1.025

For alk/calcium, I've been dosing 4cc/day, but they don't really move, so my guess is that mag is causing the issues.

Overall, the corals look okay. Aside from the birdsnest which is growing nicely, nothing is growing like I want to though. Polyp extension is moderate to good, but I know it could be better.

So I see my choices as being this, do you agree?

- bump up dosing of cal/alk/mag even more (the flux of pH makes me somewhat nervous though, so I'd like advice here)
- look into a higher quality salt mix that has higher levels of calcium/mag/alk
- consider dosing the salt water I add when doing my weekly WC. (stupid idea?)

I've been fighting this for a couple of months and am just about out of ideas as to what to do. Getting too far into chemistry gives me bad flashbacks to getting poor grades in it in high school, so please be nice Mostly, I'm nervous about overdoing it. I've been taking the dosing pretty slowly, as adding things to the tank makes me nervous.

Thanks in advance,

-greg

 

[jeffaquarius]

Your hunch is absolutely correct. Calcium won't go up if Mag is not at the right level. You can either dose Mag or do a large pwc. When dosing Mag, It will take several days to reach your target.

 

[gaker]

Thanks for the response!

Since I've been doing 3 tsp 1x/day, do you think it is safe/reasonable to go 3 tsp of the mag salt 2x/day?

ETA: Any suggestions on a better long-term plan for keeping mag higher? Having to deal with the magnesium crystals daily seems like it might become a chore as well as slightly cost prohibitive for such a small tank.

 

[jeffaquarius]

Each brand of Mag may have different max daily dosage and it's too risky to overdose. Your Mag should be increasing each day. If it doesn't you should do large pwc and resume dosing. Raise Mag first then Alk followed by Cal. You need to calculate how much your corals consume then you can split dosing each week

 

[Bige]

I would have someone else test your water. Make sure it's not your test kits. It takes a ton of mag to raise your mag. A literal ton. After your sure the kits are good then do water changes until your numbers are right. And then test your water everyday to figure out consumption. Then dose accordingly.

 

[gaker]

Thanks for the responses. I had my LFS test the water as well to help me make sure I'm not crazy.

I've gotten the mag up to about 1260 in the last four days, so I'm making progress!