Bad Salifert Ca test kit?

[rocketeer]

Has anyone bought a bad Salifert Ca test kit recently? This one has an expiration of 09-2017. I can't believe how far off this is. The first test with it used all 1 ml of the titrant and never turned blue. Two days ago with my old test my tank was under 400. I tested with a Seachem kit today and got 380.

I reread the instructions and tried again and got the same results. The test kit looks the same as the old one except this one has a smaller scooper and slightly different looking labels. The instructions are the same.

Both the Salifert and the Seachem kits use roughly the same proceedure: A little tank water, scoop in powder, add some "regent 2", then titrate. Do you think something else in the water could be throwing one test off and not the other? Mg measures 1260.

Jack

[FireWater]

I did a quick web search for others having issues and the list is fairly long. It appears that the only salifert test kit that has this many issues is the Ca.

I don't personally use the salifert kits anymore, but remember always being happy with them.

[rocketeer]

It turns out that maybe the new test is right. I took a water sample to a LFS and they measured 600. I bought a Nutrafin kit and it measures over 600. I guess the Seachem kit that always agreed with my old Salifert kit was wrong. That's five different tests, three say over 600 and two say 380. I wish I could have more confidence in this stuff. I have some old reference solution I can try. Does stuff like that go bad?

[Troy Valentine]

I had a similar issue with Salifert, except mine was with an Alk kit.. The test was reading 4.6 dkh so I dosed accordingly to get it back up to 9-10 dkh. By the time I finally got it up to 9 my coral started to bleach. I purchased another Alk kit from Louis and sure enough the new kit was reading over 15 dkh. I learned my lesson, I now keep multiple kits with different exp. dates.

[Bill S]

Good advice, Troy. I had the same issue with a Seachem alkalinity kit.

[glarior]

If you can find someone with a Ca meter I would ask them to test it.

I had a similar readings with Ph. I was reading 8.6-8.7 with my two hagen test kits and 8.1 with the salifert. Irritated I bought a Ph monitor and my water is 8.2. However, on another tank all three test kits read the same as the Ph monitor. I don't understand that but something has to be in the water messing with the hagen test kits.