What alkalinity level do you keep in your REEF?

[Myka]

Please do not vote if your tank is not a reef.

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I have found it very interesting to watch "the" reef tanks of the time over the years. Something I have noticed is 10 years ago, even up to 3 years ago Salifert test kits were "industry standard" for most of the leading reef keepers, they still are for many people. During this time, the leading reef keepers have found that keeping an alkalinity level of 9-10 dKH has given them the best results.

In the last 3 or so years Elos kits have begun to move in as the NEW (oh la la lol) "industry standard" for many leading reef keepers. People are also starting use devices like colorimeters, and more accurate test kits like Hanna, LaMotte, Hach. Many of today's leading reef keepers are beginning to suggest (and keep) lower alkalinity levels of 7-8 dKH which makes a lot of sense since NSW is close to 7 dKH.

Interestingly enough, many people are noticing that these more accurate means of testing are often reading 2 dKH lower than a Salifert test kit. I have both Salifert and Elos alkalinity test kits (both new), and I have also compared them to a Hanna Colorimeter. When I tested the same sample of my tank's water I got:

Hanna Colormeter = 7 dKH (converted from 125 mg/l)
Elos = ~7 dKH (Elos goes up in 1 dKH increments, it was pretty close to 7, as it barely changed)
Salifert = 9.15 dKH

Anyway, this is all just something that I have noticed over the years be reading tank logs, journal type books (old and new), etc. Recently, I have also heard other people talking about this. By no means is this some sort of published data. Well maybe, but I don't know where it would be.

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So long story short, I am interested to see some more evidence. So, what test kit do you use, and what level do you keep your alkalinity at?

If you have two kits, and have tested the same sample of water with both, you can vote twice. I forgot to. *smacks forehead*

[kien]

8 dkH with API test kit.

[Myka]

Thanks Kien, I actually quite like the API alkalinity test kit, it is reliable for giving consistent results, but for this particular poll I'm really more interested in Salifert VS Elos, that's why I put the API into the lower end category.

[no_bs]

Elos 8-9 for us.

[Zoaelite]

Originally Posted by kien

8 dkH with API test kit.

+1, although the API test kits are a little cheaper (around $45.00 for the reef master kit) I still find them very reliable. I haven't used many different Alk test kits but any kit relying on distinct color changes over the old Hagen "Pink nitrate test" comparison is better in my books.

[danny zubot]

I have used Salifert, Elos and API for Kh tests and find that I got similar readings with all three. Since I don't really care to know to the tenth of a degree what my KH is, I've opted to use API lately for it's simplicity. I try to keep my KH at around 9-10 Kh via my API test. It's good to know that I don't need to keep it that high though.

[Myka]

Thanks for the info Danny.

[christyf5]

I aim for around 7-9, I like to keep it closer to 9 but the tank likes to be around 7 it seems.

I too bought the elos kit after people were complaining about the salifert. I got pretty much the same readings for both elos and salifert. And the elos kit had incorrect instructions which I wasn't impressed with so I've stuck with salifert.

[Doug]

I voted 8 to 9 dkh with both Salifert & Elos. No particular preference. All through the '90,s and into 2000, I always used the cheaper FastTest or whatever the name was. Measured the same as the Salifert I used. Could buy the kits for $10 but dont see the anymore.

I like API for phosphate and nitrate, so may switch to them, as I see you guys say they make alk. test kits also.

[don.ald]

with my elos i get a reading of 6
with the API i get 8
too big of a difference??\
anyone else see different results?