View Full Version : salifert alk test expired?? 16 dKH

07/29/2008, 06:37 PM
Is it possible to have a dKH reading of 16?? I'm using the Salifert test kit. It may be 1 year old. Could it be expired?

That's right, I titrated a whole ml syringe, plus .05 of another one before it turned orange/pink. From the beginning, I've had readings of 12 and 14 dKH, but now I'm having issues with RTN or sudden death of some sort in my SPS. I have a calcium reactor, and just use RO for topoff (no kalk).

I have about 100lbs of live rock and maybe 1/2 - 1" of Argonite sand -- most of which clumped up in the first month or so, before I noticed (precipitation, I'm guessing).

If this is a real dKH reading, how do I go about bringing it down? What causes it to be so high?

btw, I use Instance Ocean for salt.

07/29/2008, 06:41 PM
Could very well be expired! I stand up for Salifert kits since I've found them to be quite accurate. I do notice that the regeants go bad after about 4-6 mo and the readings become inaccurate.

Check with a new kit and confirm the alk levels before doing anything else.


07/30/2008, 11:26 AM
My friend said it may have been due to my Ca reactor effluent running on full open (unclogging the line, then forgot to throttle it back down). Too much CO2 in the water?

07/30/2008, 11:40 AM
Yes that absolutely could be the cause. It's not too much co2 in the water, it's too much alk in the water!! Get another test kit and confirm the reading. If it's accurate then I'd do some water changes over the next few days to lower the level. Since a ca rx adds ca and alk in equal proportions, your ca is likely very high also. If you find your ca very high the alk reading is likely accurate. A very high ca can have an effect on your mag level so I'd check that also.


07/30/2008, 12:25 PM
mine shows 16 dkh too! I figure it is just off.

07/30/2008, 12:45 PM
My Ca is 400 and Mg is 1170. I'll pick up another kit today.

07/30/2008, 12:47 PM
If Jacks ca rx effluent was wide open for a period of time it's likely that he could have dosed a significant amount of ca/alk and the reading could be accurate. Won't know the truth until confirmation with another kit.


07/30/2008, 12:48 PM
With a ca of 400 I suspect the alk kit is just inaccurate. No worries. Ca reactors dose ca and alk in equal proportions so with a ca of 400 your alk is likely just fine (that is if your not dosing alk via any other means).

Sorry, previous post was put out before I saw your ca and mg readings.


07/31/2008, 03:33 AM

Are you dosing any carbon sources for bacteria? Like vodka/sugar or vinegar?

07/31/2008, 08:51 AM
Okay, new test kit from LFS (TetraTest KH--all they had) reports KH of 12.

I also picked up a Phosphate test kit, because I have green hair algae and red cotton ball algae in the sump, that grows like crazy. I didn't have time yet to test for Phosphates.

I'm debating the Vodka method to see if I can clear up the algae.

The only reactor I have is the Ca reactor. In the beginning, I used Kent Turbo-Calcium to get my Ca up, but not in a long time. I've dosed Mg in the past with Kent Tech-M, but also not for a while.

Thanks for the tip for verifying dKH.