Accuracy of Salifert's alk test kit....

[mattb]

FWIW, I've been noticing slowed growth in my sps... I measure alk every week, and after I make a change in dosing vinegar with kalk, ca rx adjustment, etc I tend to measure daily for a while to see the effects of those changes.

I was getting a consistent 7.7 dkh alk using Salifert. Well I measure with Seachem and it measured 5.4 dkh (after conversion to dkh from meq/l). I saw a thread somewhere, I believe on the zeo forum about someone tested with LaMottes and Salifert and found the Salifert incorrectly showed a higher alkalinity.

[spsick]

whether it be 7.7 or 5.4, arent they both low? mines between 9.2 and 9.6 salifert, and calcium always 400. speaking of acros :poke: tcn stuff?

[mattb]

NSW is 6.7 - 7 dKH, so 7.7 isn't, but 5.4 isreally low.

I'll post a pic later, sorry, it's been hectic...

[spsick]

ahhh... anyone else care to chime in? I thought the goal was 8-10?

[mattb]

Depends on who you ask... the reasoning to maintain higher than NSW alk is that in aquaria there are more acids that can lower it such as the nitrification cycle, which adds acids which can lower alk and pH.

[sea monkey]

salifert tests are by far the easiest to read but i get complaints all the time about the accuracy.

[mattb]

Yeah, if that's why they are so popular that's pretty sad. I'll take accuracy over readability any day. Seachem's total alkalinity is a perfect example, they had a bad batch of alk test kits, so they were sending out extra of the dye to make them easier to read. I prefer Seachem because many of their kits include a standard.