Ca
 

Can you check the oxygen levels in the tank? How about the Oxidation Reduction Potential (ORP)?

Re: Ca
 

nothing to do with precip, and difficult to test.

Ca ppt
 

Sounds to me like your Alk is not high enough to buffer the pH enough to prevent the ppt of calcium carbonate. You may be getting severe pH swings during the day/night cycle also.
Try the Randy Holmes-Farley articles on Alk,Calcium and pH in the Advanced Aquarist archives for strategies and explanations.
IMHO raising your Alk. with eg. baking soda would be where I would start.
Good Luck

Re: Ca ppt
 

Guys,

I know all about raising alk from reading Randy's and others' articles. Just don't know why I'm getting precip all of the sudden :confused: I'll post this to RC and see what they have to say.

Re: Ca ppt
 

Just out of curiosity why do you call the two tanks with ca levels of 380 low? that is the ideal value to have.

Also are you getting an accumulation of kalk powder in the bottom of your kalk jug (what ever jug you mix your lime water in and then use to add it to the tank) If you are it could be some of this being carried over.

Steve

Steve,

Yes, there is a little bit of powder on the bottom of the mixing jug, but not much. When I used 2 teaspoons of kalk per 4L, there was much more powder on the bottom, so I switched to using only 1 teaspoon of kalk powder. Either way, I would discard about the last 1/2 L of the mixture so none of the powder would get into the tanks.

One thing that I find strange is that when I pour the kalk mix into a clear 2L bottle before pouring into the dripper, the kalk mix is not clear as I would sort of expect it to be. However, I used the slightly cloudy kalk mix in the dripper and didn't have precip until my last water change.

FWIW, I mix my kalk for about 30 seconds and hook it up to the drip. No problems..

reply
 

I'm having wierd readings in my tank too that have me confused so this topic is very interesting to me. When I test my calcium I get precipitation in the test tube, but not Alk and Ph. the test is only a couple months old.

The Aqua Dose Delivery System 1400 ml from J&L are the ones I use:

http://www.jlaquatics.com/images/cleaning/aquadose.jpg

Added Kent Liquid Ca to all tanks this morning, as well as a bit of Aquarium Revolution pH and Alk Booster to the 37g, then began the kalk drips to see what would happen (kalk that is being used has been in the drip containers since a couple of days ago):

- 37g is precipitating a bit, but not nearly as much as the last time I dripped, and is still dripping
- 67g is not precipitating at all, and is still dripping
- 120g precipitated as badly as before, so I shut it down

Have to get another test kit to measure Ca in all tanks as I'm running out of titration solution :confused:

Brad,

What kind of drip system are you using? Aren't you concerned that the kalk doesn't have a chance to mix well with your RO water before it goes into your drip container then into your tank?

Danny,

What Ca test kit are you using? I use what is locally available which is the Hagen kit. I shake each solution bottle a bit before using, and I especially mix the second solution for the full 5 seconds that the kit recommends.

Bev, I make RO water in 5g jugs and stack them. When I change a jug, I mix 80 ml of vinegar and 8 tsp of kalk in a container for about 15 seconds, dump this into one of my 5g jugs, give it a shake and hook it to the float valve. pH of this is about 12, so I know it's close to saturation. So no, I haven't got any concerns about mixing.