Calcium won't budge

Justiful · Dec 21, 2015

Whatnow said:
okay I just tested my salt mix in my that I use for WC's(been mixed for 3 days with a powerhead in it to keep ready) and my salinity was 1.023 and calcium was at 420 ppm.....? now why is it that after its been in the tank for a week the calcium is down to 340ppm and doesn't change?

You have supersaturated your calcium, and it is forming calcium carbonate since your magnesium is low. It precipitated and thus the calcium is still in your tank, but is locked up as a solid precipitate. If you keep adding more calcium it will keep forming calcium carbonate. Your values won't go to where they need to be.

You need to add magnesium, (edited here) -- Do a water change, wait 24 hours test again. I would say add magnesium since it nearly impossible to Overdose, but safest bet is a water change for now. But if you got extra water on hand I would say follow the directions on bottle to raise Magnesium 300 in your tank. Even though you don't have a kit. It is hard to overdose magnesium, some people even purposefully raise it to 1800 to fight bad algae.

DO NOT add any more calcium. Do regular water changes until it levels out. All that calcium you have been adding is still in your tank as precipitate, you don't want to exacerbate the problem. Do not expect this to immediately change your calcium levels, it won't but over the next 2-3 water changes you will level out again.

I just follow the directions on my 2 part. Haven't had this problem yet myself. But I raise it very slowly over a few days.

jujuman16 · Dec 22, 2015

I am a firm believer on only dosing what you can test for. I would not add anything unless you tested it, although most of us are sure your magnesium is low, just not sure how low... Red Sea or Salifert tests seems to be preferred by the majority of the folks I know. My advice is to get that Red Sea and as you run out of them you replace them with Hanna testers, they are well worth the money. Call the LFS around you and see if they will test your magnesium. I have done it several times in an emergency and the cost was $2. It should give you an idea of where your levels are at and you can start dosing accordingly before your kit arrives.

FWIW, the sweet spot in my tanks is ~ 1400 mg.

Justiful · Dec 22, 2015

jujuman16 said:
Call the LFS around you and see if they will test your magnesium. I have done it several times in an emergency and the cost was $2. It should give you an idea of where your levels are at and you can start dosing accordingly before your kit arrives.

Great advice on the calling the fish store.

Pete polyp · Dec 22, 2015

I'm with the magnesium being low. Magnesium needs to be 3 times the targeted calcium level or the calcium will precipitate. I'm going to bet your magnesium level is around 1000.

Randy Holmes-Farley · Dec 22, 2015

So just to be clear here, magnesium at any level does not explain your inability to raise calcium when adding just a calcium supplement and not alkalinity. For folks claiming it, I think you need to think through the issue here. What it does if way too low is increase precipitation of calcium carbonate, not just calcium. For that to happen, the alk would need to be declining. If you added enough calcium for an 80 ppm rise, and saw no rise, alk would have to drop by 11 dKH. That apparently is not happening.

By far the most likely cause is that you just have not added enough. To raise calcium by 80 ppm (to 420 ppm) with Seachem Reef Fusion part 1 in 75 gallons of water will require about 227 ml of the product, and you should not be adding any extra amount of the part 2. If you added equal amounts, of any large amount, calcium will not rise much as it will lead to excessive alkalinity and precipitation of calcium carbonate.

How much have you added?

Also bear in mind that calcium kits often are not very accurate and/or precise. So trying to see small changes accurately is generally fruitless.

bobbyM · Dec 22, 2015

Yeah, What is your salinity at?

Whatnow · Dec 22, 2015

Randy Holmes-Farley said:
By far the most likely cause is that you just have not added enough. To raise calcium by 80 ppm (to 420 ppm) with Seachem Reef Fusion part 1 in 75 gallons of water will require about 227 ml of the product, and you should not be adding any extra amount of the part 2. If you added equal amounts, of any large amount, calcium will not rise much as it will lead to excessive alkalinity and precipitation of calcium carbonate.

How much have you added?

I was dosing Fusion part 1 at 1ml per 6.5g ( 75g 11-13ml dose because extra water in canister filter per day )

bobbyM said:
Yeah, What is your salinity at?

salinity is at 1.023

Randy Holmes-Farley · Dec 22, 2015

So it will take quite a while (~three weeks, assuming no demand at all from corals and such) to boost the calcium at that rate (11 mL per day), and that is probably why it does not appear to be rising. Bump that to 50 mL per day if you want to speed things along. Or buy a cheaper calcium supplement for this purpose, such as calcium chloride.

Boosting the salinity to 35 ppt (sg = 1.0264) will instantly boost calcium from 340 to about 390 ppm.

But if you do not want to do that, you need to add the amount I indicated.

Whatnow · Dec 22, 2015

Randy Holmes-Farley said:
Bump that to 50 mL per day if you want to speed things along.

awesome thanks going to do a 25% WC this evening anyways an ill test later tonight and then dose accordingly

.

twilliard · Dec 22, 2015

Thank you Randy!
I was shaking my head reading this.
People listen, he is dosing fusion.
Now if you read the bottle IT contains magnesium!

And what was this.. super saturation?
It would be a snow storm if that was the case