PDA

View Full Version : Calcium high, alk flucuates


tjm9331
09/26/2017, 01:58 PM
Hi guys,

so my 75g as been up and running now for a year and a half, I have several coral in my tank, if I had to guess, about 15-20 frags mostly LPS and softies with a couple of monti's near the top of the tank.

I test alkalinity pretty much every week and I can see that it is either being consumed or precipitating out of the tank as I have to add reef builder to bring it up from around 7dkh to between 8 and 9dkh, sometimes I have to do this twice a week.

The odd thing is that ever since I started testing calcium it's been high close to 500 and seems to never drop. I started using API test kits but then heard they can read high so I moved to Red Sea test kits and I'm getting the same results. I haven't dosed any form of calcium since starting the tank.

I use Reef Crystals for salt mix, my rocks are BRS pukani and crushed aragonite for my sand bed.

I figured once I got some corals in the tank I would start to see the calcium drop but no such luck.

I'm pretty sure the coral are doing well, I see a white ring around one of Monti's which tells me that it's growing?

My frogspawn, hammer and Duncan corals all open up during the day and my zoas are sprouting new heads.

I had read an article about how alk and cal are related so I had brought my alk up to 11 to match the high calcium. I thought the cal would drop as the alk dropped but no such luck.

could the crushed aragonite be supplying the calcium to the tank and I just need to wait for that to deplete before I see a drop in calcium?

also not that this has anything to do with it but my tank doesn't seem to want to grow any coralline algae, I know that could be a blessing but a little would be nice ;) I can tell the rock surface is calcified but no bright purple like I had hoped and nothing on the glass :(

anyways sorry for the long winded post, any input would be much appreciated

TIA

bertoni
09/26/2017, 03:47 PM
Most likely, the calcium is from the salt mix. Reef Crystals mixes up to around 500 ppm, and that alkalinity consumption rate is fairly low, so water changes might be enough to keep the calcium at that level. I wouldn't worry. The level is safe enough as is. Dosing alkalinity won't change the calcium level in any measurable way unless it's badly overdosed and causes a precipitation event, so your results are normal there.

tjm9331
09/27/2017, 06:46 AM
Most likely, the calcium is from the salt mix. Reef Crystals mixes up to around 500 ppm, and that alkalinity consumption rate is fairly low, so water changes might be enough to keep the calcium at that level. I wouldn't worry. The level is safe enough as is. Dosing alkalinity won't change the calcium level in any measurable way unless it's badly overdosed and causes a precipitation event, so your results are normal there.

Thank you for the reassurance, I'm glad to hear that my results are normal...one less thing to worry about ;)

any idea why I wouldn't be growing any coralline? Trust me I'm not going to force it, I'm just curious. I have introduced some coralline and shaved some into the water column, I'm just wondering if my corals are doing well why it wouldn't be taking off...

mcgyvr
09/27/2017, 08:10 AM
mag level? (likely fine with RC salt but always good to know)

tjm9331
09/27/2017, 11:02 AM
mag level? (likely fine with RC salt but always good to know)

Sorry forgot to post that, last check MAG was between 1400 and 1440 on the Red Sea pro kit so I was writing in my log 1420

Sk8r
09/27/2017, 11:47 AM
Coralline needs magnesium, which also helps stabilize alkalinity. A mg level of 1350 is good. Below 1200, everything will tend to come downward, alk and cal sinking with it. Your mg should be sufficient for good coralline growth. It tends to prefer aquarium walls and equipment to rock---so it's a mixed goodness.

tjm9331
09/27/2017, 11:56 AM
thanks for the replies fellas, I guess I'll just have to be patient and see what happens. Good to know though that my test results are in line.

bertoni
09/27/2017, 03:41 PM
I think some patience will solve the coralline problem, but various strains of coralline do better with different types of lighting, as far as we can tell. At some point, you might consider seeding the tank with a bit of coralline from a tank with similar lighting. Personally, I'd just wait a couple of months, and work from there.