Kalk Precip
 

Have been dripping Kent kalk mixed with RO/DI water off and on for several months with great success in my three tanks.

After my last water change on the three tanks, this past weekend, the kalk drips into the water and then it precipitates. It looks like it's snowing. In all three tanks :confused:

Haven't done complete alk, calcium, magnesium tests on any of the tanks. I'm sure they are all at least slightly different in chemistry, so I'm thinking my kalk powder is getting old.

What do you think?

Are the bottles and lines clean? if not it could be a build up of scale coming out, maybe if you can run hot water or vinegar through it.

Noticed that the kalk drip would stop and that there was kalk build up in containers and lines. Cleaned all three containers and lines two weeks ago with vinegar, then ran some RO/DI through them to get rid of the vinegar. Everything worked fine. Cleaned them again when the precip started using the above method and still precipitating.

you need to take Ca and alk measurements...

WOW......I was just reading about this........

I think it has to do with the fact that there is not enough CO2 in the water for the kalk to completly react with....... I will go and see if I can find what I was reading........

Ca
 

Sounds like it could be past saturation point.

Richard,

Would like to read what you've read. Might be helpful.

Jason and Brad,

Will test tomorrow when the sun comes up. Don't trust my eyes reading tests in overhead light.

Thanks for the tips.

One point of interest: I've been dripping kalk during both during lights on in the evening and early morning, and night. Never had a problem of precip during those day times. At night, I never thought to look for precip, well, because I'm sleeping then. However, there had been no signs of precip the next day while dripping at night. Only noticed precip a few evenings ago. Tried to drip early the next morning and still had precip.

this is not it.......way to many articles........ :eek:

but try these

http://www.advancedaquarist.com/issu...e2002/chem.htm

http://reefkeeping.com/issues/2003-0...ture/index.htm

hope this helps

Yup I think PH is where to start

Good luck

Couldn't wait to test until tomorrow. Here's what I found:

37g:
- SG - 1.026
- pH (10 mins after lights out) - 8.19
- alk - 5 dKH (very low!!)
- Ca - 320 ppm (very low!!)

67g:
- SG -1.024
- pH (10 mins after lights out) - 8.34
- alk - 6 dKH (very low)
- Ca 380 ppm (low)

120g:
- SG - 1.025
- pH (10 mins after lights out) - 8.36
- alk - 8 dKH (a bit low)
- Ca - 380 (low)

Okay. Alk and Ca are low in all tanks, some lower than others. So why would my kalk precip in these alk and Ca starved environments?

Before the precip problem and after the precip, I have used the following to see what difference vinegar made to my tanks:
- 1 teaspoon kalk to 4 L RO/DI
- 1 teaspoon kalk to 4 L RO/DI plus 1 teaspoon vinegar
- kept kalk mixture tightly sealed and let it sit 24-48 hrs

No difference in precipitation using vinegar or not.

Maybe I should buy some new kalk powder and see what it does...

Bev, you're right. Those values do not set the environment for precipitation. My kalk is over a year old, sits open half the time, never does that at all.