Reef Crystal users beware

[Hendersonracing]

Ok I have been using this salt for 2 years now...and have had few problems...but I decided to do a big wc and noticed something weird


I was planning on doing a 90 gallon water change on my 210 reef


I have been running it now for 28 hrs at a salinity of 1.026

my calcium reading was 360 but my ALK WAS 15.7DKH


I used 3 different kits(salifert) and measured each bucket 3 times with the same reading....has anyone else had this problem???

I don't want to freak out my corals with a VERY HIGH DKH reading like that??? also I have been using salifert for a long time

my tank has a dkh of 7.8 and calcium of 450..

THANKS Joe

[Curve50880]

Ive been using reef crystal salt for past several months and my levels have been fine.

[BigRedSpecial]

My alk levels actually went UP when I switched from reef crystals to IO; RC was reading 360Ca and 9DKH; IO is reading 340Ca and 11DKH consistently.

[lilchris]

I know there was an issue that the Salifert ALK test kits are not accurate at all. I know some people used the API test kits to bump it up against the Salifert kits. I would post this in the chemistry forum also check the Salifert vendor forum. There is a guy on there billybeau1 (i think) he has alot of information about this issue.

[Craig Lambert]

There are a number of batches of Salifert Alkalinity kits floating around that give dKH readings 2-4 higher than they actually are. There are anumber of threads on this at the Salifert Vendor forum on RC. You might want to read a few of them and see if you have one of those bad kits. I doubt your RC is the problem.

[Hendersonracing]

my tank has a reading of 8 and the salt is 15 same kit?

[Craig Lambert]

That may not matter. The errors are exponential. You need to check the batch numbers against what's posted on the forum.

Also, comparing tank water to nsw is meaningless because your tank depleats Alk on a daily basis. (Mine depleats about 1.6 dKH per day when maintained at 9dKH). NSW is always going to test higher than tank water. (Much higher if you aren't dosing daily to maintain your alk level).

[Hendersonracing]

thanks!!