Am I dosing right?

[Benhuan]

Hey all,
So I have a nano which has been setup for around 5 months now. I currently have around about 10 acro frags which have been doing well and colouring up really nicely in the past month. However, I can’t help but wonder why my calcium isn’t dropping at all and why magnesium is fluctuating so much. I currently dose alk and magnesium only. I am using solutions made by my LFS. I have attached my parameters as photos on reef trace app below. I find it weird that the tank is consuming alk and mag only. Should I be dosing alk and calcium in a 1:1 ratio?
thank you and please let me know if you guys have any insight.

 

[rmurken]

I take it from the screenies that this is a 15L or 15G tank, right?—but either way, how big are your water changes, and how often? That might be a factor in making it seem like you’re consuming less Ca than you are.

Also, Ca numbers move much more slowly than Alk, so I’d really just look at Ca numbers from week to week. Daily Ca measurements will have a lot of noise. You don’t have a decrease over the course of the week here—it’s basically unchanged. Maybe water changes are swamping the signal?

I’m suspicious of the need for a lot of Mg. I could be convinced it’s mostly lack of precision in the test, especially since the results are so close together. And your trend is basically upward, presumably from supplements.

I’d also get the download from your LFS on what’s in their supplements just to see what they may be doing.

Yes, Ca and Alk should be dosed in a reasonably fixed proportion, but 1:1 is just a function of how 2-part additives are typically made. The manufacturers (or Randy) work out concentrations for the Ca and Alk parts so that you can add equal amounts of each since it’s easier. Hopefully your LFS is doing that. Mg is different and not typically mixed up that way.

 

[Benhuan]

I take it from the screenies that this is a 15L or 15G tank, right?—but either way, how big are your water changes, and how often? That might be a factor in making it seem like you’re consuming less Ca than you are.

Also, Ca numbers move much more slowly than Alk, so I’d really just look at Ca numbers from week to week. Daily Ca measurements will have a lot of noise. You don’t have a decrease over the course of the week here—it’s basically unchanged. Maybe water changes are swamping the signal?

I’m suspicious of the need for a lot of Mg. I could be convinced it’s mostly lack of precision in the test, especially since the results are so close together. And your trend is basically upward, presumably from supplements.

I’d also get the download from your LFS on what’s in their supplements just to see what they may be doing.

Yes, Ca and Alk should be dosed in a reasonably fixed proportion, but 1:1 is just a function of how 2-part additives are typically made. The manufacturers (or Randy) work out concentrations for the Ca and Alk parts so that you can add equal amounts of each since it’s easier. Hopefully your LFS is doing that. Mg is different and not typically mixed up that way.

Hey, thank you for taking to time to reply.
Sorry, the tank is a waterbox peninsula mini 25, so 25 gallons. Seems like i wrote it wrong in the app.
I do a 15 litre water change every week mixing red sea blue bucket to 35 ppt. I have switched from another salt that mixes alk at 7.5 dkh and yesterday was my 3rd WC after the switch. I am also confused to why mg is being used up so much however, if I do not dose 5.5ml of the solution daily the mg seems to drop around 50ppm everyday the 1200 mg you see was me not dosing and so I started dosing mg to try and bring it up to 1350ppm as I noticed my digis were not doing as well in the lower mg. I do have a small/medium clam in the tank but I doubt that size would be doing too much on the 3 elements. Since my calcium isn't budging maybe due to WC I'm not sure, and i dose 5.6 ml of alkalinity daily, should i dose 5.6 ml of calcium?

 

[rmurken]

No problem! But I’m afraid I don’t have more to offer — Mg getting consumed faster than Ca (that isn’t even being dosed) is not a thing I’ve heard of.

My instinct is testing error, WC’s handling a lot of your consumption, and maybe something goofy with your two-part. I’d definitely have your LFS give you precise instructions and tell you what’s in each part.

@Randy Holmes-Farley or others may have a more incisive view of things.

Dosing Alk, Mg, and no Ca doesn’t seem like something you’d want to do for the long term.