Calcium test question


New Member
I have the Hagen master test kit, and when testing my calcium it I continuosly get readings of 540-560ppm. Is this test flawed? I find it hard to believe that a lot of people have trouble maintaining 400ppm and I am way over that. I use RO/DI water with instant ocean, and my tank is lightly stocked with LR, LS, a few fish and a few corals.


Active Member
I had the same problem. I was using Red Sea calcium test and was getting 400-410 ppm readings. Then i bought Hagen calcium test and got reading of 540-560. I tried meny time testing with Red Sea and Hagen and still had the same differences. IMO Hagen is wrong. So this is just waste of money. Because it is very hard to maintain 540-560 with just liquid calcium additive. By the way does anybody know "Tropic Marine" test kits. Are they good? My LFS guy said they are very precise.


I think that you probably due have a high calcium level, due to your lightly stocked aquarium and regular water changes using quality water. 560 is a little suspitious tough, and is due to a faulty test kit(more than likely). I only use La Motte professional test kits, so I don't know of your test kit. Though you will find that a lightly stocked well mantained aquarium will sustain with out the addition of many addatives.

nm reef

Active Member
I am not familiar with the Hagen test kit...I use salifert. Is it possible for you to have your water tested by another reefer or maybe a trusted LFS...then compare the results.It does seem to be a bit high....but it could be accurate. Also possible that the results are wrong too.I trust the test I use but I still have a trusted LFS run a series of tests about once every 3-4 months just to compare results. Better safe than sorry!