API and Salifert Calium and Alk Tests

[jason2459]

Well, with all the buzz going around about calcium and alkalinity tests I decided to try something out with API and Salifert. Seemed like in the two major threads going about the two types of tests API was left out of two structured tests that were done and published.

Note: I am not a chemist or a scientist or anything close to it. Just your standard below average reefer! :bum:

This is mainly for me and if it helps anyone then great or hurts anyone else then that's your fault. I have only been testing alk and calcium recently (about a year now) and don't have any background with any other company's test kits other then API. Mainly because I found them to be very easy to perform and easy on the wallet. They always seemed consistent to me as well so figured they would be accurate enough for me as well.

I've been taking the tests just as an indicator of trends so being spot on is not important to me. I don't do anything like the balling, balling light, 2 part, etc.. and just recently starting placing Mrs. Wages lime in my ATO container. So, I just want something close and consistent.

The recent alk and calcium threads have gotten me curious enough to check against Salifert as it seemed as something fairly consistent and reported as being designed for marine use and not freshwater. According to the alk thread it seems to read a little high.

So, here's the tests along with a few other parameters I also tested tonight.

Note: I am due for a weekly water change tonight, ATO has been turned off all day to let kalk settle after fill up, and I will be dosing a weekly dose of magnesium tonight after the water change.

Temp: 84.6
pH: 8.01
Salinity: 35 ppt
Mg: 1260
PO4: 0
Nitrate: 0

Calcium:
API (Manufacture Date: April 2009) what I've been using the past year
test1: 420
test2: 420

API (Manufacture Date: May 2009) Just bought this week
test1: 420
test2: 420

Salifert: (Expiration date: 05-2015) Just bought this week
test1: 400
test2: 390
test3: 400


Alk:
API (Manufacture date: May 2009) what I've been using the past year
test1: 9
test2: 9
Salifert 7.1 Std: 8

API (Manufacture date: Jan 2010) Just bought this week (not to thrilled with the date)
test1: 10
test2: 9
Salifert 7.1 Std: 8

Salifert (Expiration Date: 07-2015) Just bought this week
test1: 8.6
test2: 9
test3: 9
Salifert 7.1 Std: 7.4 (got lucky had just enough Standard to complete three tests off of)

I found the Salifert tests pretty easy just like the Magnesium test kit that I've been using. I did not like the KH-IND agent in the Alk kit as it was messy and I had to make sure to wipe the top off before dripping into the test vial and also needed to make sure to tip it over the napkin first before placing it over the test vial to drip into. It does have the ability to get a higher resolution then the API especially for the Alk kit. I liked that the Salifert came with a reference solution for the Alk as well.

So, what I think I got out of this is that the API test kit is accurate enough for me and really really easy to use. If I needed a more granular results the Salifert is probably what I'd use.

I did a water change after getting the tests done and dosed a 1/4 cup of magnesium. ATO is turned back on. I'll do another set of tests tomorrow night.

 

[OwenInAZ]

I like API tests for the reasons you list. Cheap, accurate enough for our purposes and easy to use. Nice to see they hold up against the Salifert!

 

[shifty51008]

I agree, after using salifert for years and testing them out against API that I can get around my area alot more easily, I have switched to using API on everything except p04 and mag.

 

[gnashty]

I used API too for a while, calcium mostly and it did ok but my Elos is still a little more accurate imo. My problem with API is the Nitrate test, it will read 40 ppm and my Seachem kit reads .1-.2 and is verified by LFS testing.

 

[shifty51008]

I used API too for a while, calcium mostly and it did ok but my Elos is still a little more accurate imo. My problem with API is the Nitrate test, it will read 40 ppm and my Seachem kit reads .1-.2 and is verified by LFS testing.

just remember with the nitrate API test kit you have to shake bottle 2 for a while. most people had the same prob. as you and after shaking the crap out of the bottle and even hitting it on the top of the desk or something the test was much better

 

[jason2459]

Yep, you have to shake the snot out of bottle #2. I bang it on a hard surface several times as well. Also, it was pointed out in another thread that you're supposed to hold it vertical when dripping in and not at an angle.

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[jason2459]

Results from tonight were as expected as I did the water change last night, dosed 1/4 cup of Tech-M, and started the ATO with kalk in it back up last night after the water change.

Temp: 81.2
Salinity: 35
pH: 8.21
Nitrate: 0
PO4: 0
Mag: 1320


Calcium:
API (Manufacture Date: April 2009) what I've been using the past year
test1: 420
test2: 440

API (Manufacture Date: May 2009) Just bought this week
test1: 440
test2: 440

Salifert: (Expiration date: 05-2015) Just bought this week
test1: 410
test2: 410
test3: 410


Alk:
API (Manufacture date: May 2009) what I've been using the past year
test1: 9
test2: 9

API (Manufacture date: Jan 2010) Just bought this week (not to thrilled with the date)
test1: 10
test2: 10

Salifert (Expiration Date: 07-2015) Just bought this week
test1: 9.6
test2: 9.6
test3: 9.9


Alk between API and Salifert seem right about on minus Salifert having a lot higher resolution. Also, seems like the older the API(probably most test kits) it gave a result to the low end at 9 and the new averaged up to the higher end at 10. Salifert with a higher resolution got it about in the middle.

Both showed an increase in calcium and API was still higher then the Salifert. Both with in an acceptable range for me and pretty consistent yesterday and today including the expected increase. I bet if API had a higher resolution then it would probably be reading around 430 and that would match up to yesterdays results of about 20ppm higher calcium reading of API compared to Salifert.

 

[scubasteve06]

I use API test kits for KH, Ca, NO3, and PO4. I don't like the salifert tests as much because I have a hard time getting one drop to come out of that itty bitty tip on the dropper one at a time. I am interested in the Elos kits as they look just as easy to use as the API test kits, yet seem to be more detailed when it comes the NO3 and PO4.

 

[preef]

The API Nitrate test is awful IMO. All of the colors look the same to me. Much happier with the Salifert nitrate test since you can get acurate readings down to 0.1 by looking throgh the sample sideways.

I stopped using API when I bought a new Alk test and the level was completely different than what I had with the old. I use salifert for everything now except phosphate. I use Hanna for that now.

 

[jason2459]

Interesting in that if one thing I get out of an API test kit is that I've always gotten consistent results. I like that I can pick them up at every LFS around me and can check their manufacture date before I buy. Nitrate test kit does require you to take your frustrations out on the second bottle. API doesn't give as small a resolution on most but I'm not looking for a lab test kit either. Just something easy and consistent. I would say the only one I don't like because we do need a smaller resolution and in lower ranges is PO4 and I go with the hanna for that too. API just doesn't go into the lower ranges. Mg I go with Salifert only because API doesn't have one.

I test for the following and always try to land in the following ranges, what I test with and why:

Calcium ~420-480 API: consistent, easy, and resolution handles this range just fine
Alk ~8-11dkh API: same as above

Nitrate <=5 API: same as above I don't care about the rest of the colors because if it's above 5 then I need to do something.


Mg ~1400 +/- 100 Salifert: fairly easy, consistent, seems accurate

pH ~8.1 - 8.4 Hanna handheld probe: very easy, very quick, and I get my temp and ORP at the same time.

PO4 = ~0.00 - 0.01 Hanna Checker: very easy, seems consistant for me so far, resolution meets the need and yes that is a very low target number only because of the accuracy of the checker allows for +/- 0.04 and with PO4 it doesn't take much in my tank for cyano to rear it's ugly head. I assume if it says 0.00 to 0.01 then I'm right around 0.03 which is the true target.

I must also say I'm pretty anal about doing each of these tests exactly the same way every time. Now if it's the right way I don't know and have learned new things in the chemistry forum to improve my methods but I make sure that I do the exact same steps and procedures every single time I do them. I think that helps a lot as I really think most testing errors are human errors and after that reagents that are either bad or expired.

 

[Chris27]

I've been doing this reefing thing a couple of years and come to love my API kit's. I use them for QT (ammonia, nitrite, nitrate) and for my display (alk, calcium). I'm stuck using a Salifert test for Mag, but it lasts a while so I don't mind dropping the $30 once a year.

All in all, with the exception of resolution, they are no different or less accurate then any other kit on the market. Tie that together with ease of use, cost and availability, you can't beat them.

There will always be haters out there that love bragging about the $300 in test kits they have under the tank, but realistically can get the same results from $75 in API kits.

 

[jason2459]

I can totally understand someone wanting more precision but it's not what I need so API fits the bill for me for most all tests except PO4 and salinity and for those I don't use API. Well salinity for obvious reasons. When high resolution on anything is wanted or needed API is probably not the right test kit. Like I pointed out above for most all tests I do I look for a wider range and track the trends. API is perfect for me for that. I pretty much started the thread because I really haven't seen the API kits compared like the others have and just plain curiosity. Certainly not to degrade any other test kit out there or the need for them. But doing those tests did help reassure me that the API kits are accurate enough for me as I've posted about that in other threads regarding my trust in any hobby grade test kit out there.

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[scubasteve06]

I agree totally with you people bad mouth API I guess because they are cheaper than salifert and the notion in this hobby is if it's cheap then it's junk. That may be the case with filtration and lighting equipment etc, but API is good IMHO.

 

[rebelson]

Hmmmm thank you for posting your test results on both kits. I'm a big fan of salifert.....but the price tag hurts. It's good to know that API is right up there as far as accuracy goes.

 

[bdsage]

I was thinking...to get better resolution from api-alk. if i test 10ml of water instead of 5ml? so 14 drops of titrant would be 7dkh,15=7.5 ect. would this possibly work?

 

[jason2459]

I would think dilution would be better with 50/50 ro/di

 

[jason2459]

I'll actually be doing another round of this with API, Salifert, and Aquamedic AWT testing next week.

 

[disc1]

Yes, if you use double the sample you would cut the reading in half. Cutting the sample with RODI won't work though. You would still be counting the same number of calcium ions. With a titration like that you can add all the RODI you want without any change in results. In the lab, we will often use a squirt bottle to knock half drops out of the burette into the sample.

With colorimetric tests like a nitrate test things would be different.

 

[jason2459]

That makes sense thanks.

 

[bdsage]

thx guys