View Full Version : Calcium Slowly Rising - What to do?

10/07/2012, 07:56 PM
Hi Gurus. May I have some help, please?

I do two 10% water changes per week--one on Sat/Sun and one on Weds. I use Reef Crystals at an SG of about 1.026. My tank is full of zoas and LPS (list is in my signature, below, assuming it shows up). I recently cleaned my power heads, which had been covered by coralline.

I never had to add much calcium (~5 ml per day). Since I cleaned my power heads, my two water changes are now adding a little more calcium than my tank needs. I still have to add alk daily (~25 ml of BRS Randy's #1 daily), but I'm not adding calcium any more and calcium is slowly rising. With calcium slowly rising, I wonder what to do. I really don't want to reduce W/Cs (I feed quite a bit) and I don't have a sump, so I don't want to carbon dose (Randy's statement that the bacteria have to grow somewhere has me thinking it will grow in my display tank).

Two thoughts come to mind:
1. Do the second weekly change with Instant Ocean instead of Reef Crystals. That will keep the sodium level right, but Mg and trace elements will be low (I can handle the difference in alk by adding more). I have a bunch of Mg that I never use and I can maybe add a little more Kent Trace minerals, to make up for it.
2. Do the second weekly change with Reef Crystals at ~80%. That will add more alk and trace minerals and Mg, but sodium will be a little low.

Thoughts? Thanks in advance.

10/08/2012, 06:46 AM
Try a 50/50 blend of IO and RC. Or, just go to straight IO and then recalculate your dosing. What are your parameters and what is the Ca trend now? Are you using a calibrated reftactometer? I wouldn't reduce your salinity.

10/08/2012, 07:01 AM
Is your newly mixed water high in Ca? And I have been using nopox carbon dosing with no sump and it's working great.

10/08/2012, 10:16 AM
Thanks, downbeach. I like the idea of going 40/60 or 60/40 (I use 5 cups per 5 gal bucket and could use 2 cups of one and 3 cups of the other). That'll keep Na correct and give me some additional alk and trace elements.

Dapg8gt, I haven't checked my mixed RC calcium lately, but I think the sticky lists RC calcium at ~490. I tested it once and I recall it being close to the number shown in the sticky.

Marcio T.D.
10/08/2012, 12:39 PM
I would go with a mix of IO and RC in one of the weekly WC and see if the calcium still keep raising. I so, go for both WC with the mix.

10/08/2012, 04:57 PM
What is the calcium level of the RC? It's likely safe enough. I'd probably just live with the higher calcium level or switch to another single salt, being the lazy type.

10/08/2012, 06:44 PM
Thanks, Bertoni. I guess I never considered just living w the higher calcium. Seems like I must've bought into the nominal 435 ppm calcium for my target alk of 3.5 mEq/L.

My current calcium is ~465 ppm. RC is listed at ~490 ppm.

My corals seem fine at the higher calcium. They are very sensitive to alk changes, but seem ok over a wide range of calc. Maybe just live w it until the caralline grow all over my power heads and my tank starts using more calc...?

10/08/2012, 07:46 PM
Oh, how I wish I had too much coralline :) May I ask what is nopox carbon dosing?

10/08/2012, 07:49 PM
oops...nevermind about the nopox, I looked it up - doh!

10/08/2012, 10:03 PM
Personally, I'd just let the calcium drift up and see whether there were any problems with precipitation. If not, I think all the organisms will be fine.

10/09/2012, 12:16 PM
Thanks, Bertoni! Sounds easier than I was thinking....

10/09/2012, 01:46 PM
You're welcome! Good luck!

10/09/2012, 07:46 PM
Agreed. At those levels, I wouldn't worry about it. Just make sure your Mg is in line and you should not have an issue.