Ca very high - how to fix?

[cvonseggern]

I finally got Ca and alk test kits, and I'm seeing that the levels in our 100g are badly out of whack. Carbonate hardness tests at right about 6 dH. I understand this to be low, but I'm more concerned about the Ca level of 555 mg/l. The table I'm using suggests Ca should be around 390 to balance with the low alkalinity and 420-430 as a goal. With Ca/alk that far out of balance I can't understand why I'm not seeing any precipitation.

So, how do I lower Ca? The only way I know of is to let animals use it up. Anything I can do in the absence of hard corals to get calcium down while I try to raise alkalinity?

Thanks for any advice,

Chris

[Tim Marvin]

I keep my calcium there. Are you mixing Oceanic salt for the tank? If so it is always high. Dose buffer and your tank should come around, Alk will rise and calcium will drop a little. Be happy most people have a hard time keeping calcium levels high.

[cvonseggern]

Thanks for the advice, Tim. I *was* using Oceanic, until I ran out recently and bought a bucket of Instant Ocean in desperation. I'll be going back to the Oceanic when the IO runs out, though. It's cheaper and seems to mix much more easily.

What would you recommend for a buffer? B-Ionic? I've heard of people using baking or washing soda, but I'd have to go back and check those threads cause I can't remember which type will raise what :P

Chris

[Tim Marvin]

I use kent buffer, but I also dose kalk which helps. You will notice a big drop in calcium with the IO.

[scuba_steveo]

555? That is past saturation...I think? Test again.

[Instar]

You may see some bleaching at 555 calcium. Add buffer slowly or just do some more small water changes. Either will bring it down. Don't try to change (raise) that dKh too fast or you will end up with trouble. All sorts of things use calcium, not just the stoney corals. It didn't get the buffer system wacked over night so correct it just as gradually.

[NaCl_H2O]

What test kit are you using, and are you topping off with RO/DI? Some Ca test kits will show false high readings if TDS are very high.

[cvonseggern]

That may well be the issue - I know my RO/DI unit is overdue for a cartridge change. I don't have a TDS meter, but I've been using the thing for about 7 months to provide water for 4 tanks.

I'm using a SeaTest kit...not the best in the world, I know, but I just couldn't get myself to shell out $45 for the Tunze kit. I tested twice with similar results. Do any of the local stores in SA provide TDS testing? I'd be curious to see what the TDS in my RO output is right now.

Thanks,

Chris

[scuba_steveo]

Salfert test kits are inexpensive and good

I do not have a TDS meter but I am getting one!

[alton]

Same problem, I switched to instant ocean to lower the calcium level. Check your Magnesium level it will probably be low also. What I did was 50% saltwater and 50% DI and Multiplied by two to get an accurate reading for calcium. I do use RO but not DI for water changes.

[NaCl_H2O]

That may well be the issue - I know my RO/DI unit is overdue for a cartridge change.

Toping off with RO/DI, even one that isn't working great, should be keeping your TDS down. Folks that top off with declorinated tap water can get a HUGE TDS buildup over time. It is probably just high Ca (450-500) and your test kit isn't acurate at that level. Try testing with 1/2 Salt 1/2 RO/DI and see how your test kit does with that?

When you can, pick up a Salifert Test Kit - I saw they had some under the counter at Alamo Aquatics yesterday!

[GaryP]

Aquatic Warehouse and Fin-Addict also have them.

Gary