calcium test kit results??

[Doug/Shirley]

I have used 3 different calcium test kit and seem to get the same results from each kit. First the Nutrafin brand After adding over 40 drops of regent 3 I achieved no color change. That would put the calcium level somewhere above 800 mg/l. The Nutrafin kit was a new kit. The other 2 test kits yielded the same results. I never could get the test samples to change color. I still got the same results after a 25% water change. Is it possible to have such a concentration of calcium w/o precipitation?

 

[Randy Holmes-Farley]

It is possible if either or both of the alkalinity and pH are low.

Try measuring the calcium level in your salt mix. What mix is it?

 

[Doug/Shirley]

Salt type: Instant Ocean
alk: 2.5
ph 8.0
I'll have to mix up a batch of I.O. and get back to you on that.
I do use ro/di well water that tends to be low in ph. I fight to keep the ph level up. I dose a little sodium bicarb each day using your recepe #1. I'll check the validity of the Milwaulee ph meter tomorrow a.m..

 

[Randy Holmes-Farley]

Then that calcium at 800 ppm could be real. It has the same supersaturation as pH 8.3, alkalinity 4 meq/L, and only 250 ppm calcium. Such precipitation is driven heavily by pH and alkalinity.

This article describes how to lower it by supplementing alkalinity and letting calcium fall on its own:

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

 

[Doug/Shirley]

I have the above mentioned artical in my archives. Thanks once again for being there!

 

[Randy Holmes-Farley]

You're welcome.

Good luck.

 

[Doug/Shirley]

After adding a little extra sodium bicarb solution this morning to boost alk and ph the water became quite cloudy I assume the calcium is precipitating out of solution. .The ph has also dropped to 7.8 Can you link me to another article for help!

 

[Randy Holmes-Farley]

Yes, it may have been precipitation of calcium carbonate. That's OK. If the calcium is really high, it may happen.

If the water is cloudy, an alkalinity test will be unreliable because it will count CaCO3 solids as soluble alkalinity. Once the water clears, check alkalinity again and dose more as needed.

This article discusses reef precipitates:

What is that Precipitate in My Reef Aquarium?
http://reefkeeping.com/issues/2005-07/rhf/index.htm