Dkh V Alk

[dmorel]

I bought a Salifert KH/Alkalinity test kit when we were in buffalo last saturday. I have tested my reef with it twice, and both times the measurement is off the charts.

When I measure with my red sea PH/KH test kit I come up with ~3
(from memory I think it was 2.8 and if I remember correctly NSW is ~2.4 or 2.5)

Now the Salifert kit has results for both alk and KH, but both are based on the results of the single test. From reading I understand that KH and Alkalinity are considered closely related in our hobby, but are not in fact the same thing.
Could it be that I have a fine alk, but my KH is way out of control?
Is this something I should worry about.
And what's the deal with this Salifert test kit?

I have a probe for my PH, so I tested the red sea PH kit and they (more or less) agreed.
My calc seems a little low with the Salifert kit (also got that saturday) at 350, measures about the same with red sea kit there too. [going to try adding some two part to bring it up and then hope the reactor keeps it stable. I had to increase my bubble rate on the reactor a little bit, I don't think it was doing all that much for the last few weeks because I was not pumping enough co2 into it. Time will tell.]

I guess my concern is with the KH.
Does anyone who knows more about KH and it's relationship to alk and calc have any input on what the best next steps would be?
I will see if I can find another KH kit locally in the next day or two and test again, perhaps I just got a bad test kit...


The tank itself seems to be doing rather well, and I am keeping a very close eye on it the last few weeks just because of all the changes I have made. (It does in fact seem to be paying off...)

another long one from me, sorry...
thanks as always for your thoughts,
-dm

[kmagyar]

From what I have read, understand, and experienced. Alk and KH are one in the same. KH is german for Carbonate Hardness. Alkalinity is the only measurment I have ever been concerned with. Thinking about both may just confuse a conversation IMO. The higher your alkalinity, the more stable your PH will be. Yet, too high of alk will drop CA in some cases. I seen that happen when I was tunning my homeade reactor. Using one of a 2 part system can help stabilize a system for a reactor, but you may not need to do that if your alk is 2.5 and your ca is 350. Thaty are both very good. They could be higher, you would only need to turn up the bubble rate a bit. Be very patient when adjusting a reactor. My old unit took 2 months. I now keep my alk at around 3.0 (that equals around 11 or 12 dkh for anyone that cares). I know you have a reactor so you might want to know how much air and effluent I use:

Bubble rate: At most 40 per minute
Effluent drip rate: a steady drip (equals 30-35 ML per minute)
Effluent alkalinity: I beleive it was around 5mq/l I can test that again.
Effluent PH: 6.8

Keep in mind thats a full sps tank sucking allot of calcium out.

[ReeferMac]

If the test kit doesn't read properly, check it with something, try testing RO/DI water, and then the waste water from your filter, and see if it register's a difference...
Also, double check the instructions. More than once I've had to re-do test's 5 times because I didn't read the direction's carefully enough.


As for the other stuff, Keith's got it right... they are basically the same thing. One is a different chemical component than the other, and the method of expression is a little different (ppm something-or-other vs. degree's of hardness). Short answer is it's how hard, or how well buffered, your water is. The more greatly buffered it is, the more stuff there is in there to suck up that excess CO2 that drive's the pH down. That stuff is your alkalinity (forget what the chemical component's are.. chucker'll prolly know). That stuff is also what corals make their skeleton's out of, what Corraline algae plates and make's itself hard with, and a bunch of other stuff in the tank. That's why we've always got to keep adding more and more into the tank. The more you've got, the more you use. To that point, and I mean no offense, you're probably not even going to need half of what Keith's dumping into his tank every day with that Rxr setup.
With a lo load on your tank, I think you'll find minute adjustments will give you a greater fluxuation in value's. It also may take a couple days to stabilize. Not having ever run one I can't comment personally, but have heard that Rxr's aren't that good at raising Calcium and Alk value's anyway... they're great at maintaining them, and IME do a better job than anything else, but have a hard time getting it up, so to speak :D
Likewise the two part additives are only so-so at raising value's. They do it for the short term, but their effect always seems to fade away on me after a day or two. I've also learned not to sweat the number's too much... just worry about getting things close. Tank's are too dynamic to try and hold it to an insane tolerance IMO. But if you really wanted to raise things up a bit, mix up a couple liter's of Kalkwasser... load's cheaper, not too hard, and works dyn-O-mite!

- Mac

[DanGlock23]

Go here:

http://www.reefkeepers.org/sps/Alkalinity.html

If you really want to get into it - try this:

http://www.ozreef.org/reference/alkalinity.html

Should answer all your questions. Water changes - rather than Calcium Chloride or buffer solutions are recommended in this article.

Dan

[Stoli]

Dave:

When I first set up my reactor, I used Seachem's Reef Calcium to get the calc up to 450. It has stayed there ever since (variations not more than 5% in either direction). I also used the Seachem buffering product. I think it works faster, easier and cheaper than Bionic. JMHO.

Stoli.

[kmagyar]

I've also learned not to sweat the number's too much... just worry about getting things close. Tank's are too dynamic to try and hold it to an insane tolerance IMO.

Amen to that. I used to get really caught up in numbers. Only patience can give you results.

[_ShotgunShrimp_]

B-ionic wont raise numbers either its ment to maintain them.... you need heavy artilery to raise.... thats why the b-ionic didnt do so well.. you could add both parts in tripple doses and probably not get a raise of very much at all.... hence people leaving the b-ionic behind when they get to those ammounts cause it just isnt feasable to do anymore...

[cperson]

dmorel,
Reefermac's suggestion on reading the test instructions carefully is a good one. I was using too much water at first - 5ml instead of 3 in the calcium test. I would recommend using the lower resolution tests, you get 2X the tests from the same kit and who cares if your calcium reading is 425 or between 420 and 430. More amens, please.

FYI: NSW = 8dKh or 2.9 meg/L, and approx 425 ppm calcium.

A good way test if your kits are in the ballpark is to test new salt water @ 1.023 sg and 77*F(aerated 24 hours). The readings should be close to NSW above. If you want I can stop over and try mine on your water. Let me know.

Toss the red sea alk test kit, they suck IMO. Inconsistent.

[ReeferMac]

Toss the red sea alk test kit, they suck IMO. Inconsistent.

Likewise. I've got LaMotte's for Alk and Ca. if you want to try those out... bring a water sample by.

- Mac

[dmorel]

I read the instructions very carefully, and then re-read them a few times.
I'm doing the test right, and the sailfert calc test is fine...

I know that the red sea kit has a bed rep, but in this case I hope it's working, cause if it isn't then I have a DKH that is off the freaking charts.

I haven't made it out anywhere else yet, but I will try to get a new kit asap to see what happens. I don't want to go messing around unless I have to.

-dm

[ReeferMac]

Take a sample up to Carribean and ask them to test it for you. It's free, and you get an excuse to go to the LFS :D

- Mac

[dmorel]

Back from CF, alk was fine.
Got a bunch of hermits and snails too and a frag...
Ugh, I'm an addict.

[Playfair]

I've never heard of any probs with Salifert kits...

Are you sure you are doing it right?
4ml tank water, 2 drops of the squeeze bottle, then start dripping a full syringe of the bottled stuff (including the air bubble) and mark how much it takes...

If in doubt, I may be able to get over this weekend and will check against your kit. CF uses Red Sea, I wouldn't trust that against a septic tank.

BTW, if you haven't found out yet, dKH and meq/l are the same thing, different units is all. I shoot for 400 Ca, and over 3.2 meq/l or 8 dKH alk.
If you were truely "off the scale", then your Ca would crash.

[dmorel]

Dave,
I hear ya.
I followed the directions to a T, and the color just doesn't change before I run out of the reagent from the small syringe.

I added a splash after the last time I tried it to make sure that it would change at some point and it did.

I will try one more time, maybe having my wife read the directions first and supervise me.
I feel certain I am doing it exactly as I am supposed to, and I have tried the test three times, but if I am doing something wrong, I did it wrong all three times...

BTW, Bryan is coming tomorrow afternoon 3-4 range.
My tank is nothing like the show tanks you guys have, but you're certainly welcome to come see it if you want. (anyone else following this thread as well)
There is talk of beer and running rj-45, take that for what it's worth.

-dm

[cperson]

Davem,
Maybe there is too much air in the syringe, maybe defective? The level of reagent should be about at the 0.8ml mark on the syringe when the bottom edge of the stopper is at the 1.0ml mark.

Are you slightly color blind - I'm not being sarcastic. Maybe you can't detect the minor change.

I would let saltwater paradice know they sold you a faulty kit if that's the case.

[ReeferMac]

I would let saltwater paradice know they sold you a faulty kit if that's the case

I would demand they take it back and give me a new one off the shelf (which I would test on their water before leaving the store to be safe), or else demand that they give me my money back (including sales tax). That's BS, and any decent store will give you a new one on the spot.

- Mac