Aquarium water testing

[madmax7774]

For those who are interested: Aquariumwatertesting.com has done an independant and unbiased review of the majority of popular salts in the hobby. They results are linked below for your reading pleasure:

 

http://reefsaltanalysis.googlepages.com/AW...alysis_0208.pdf

 

I must say that I found this to be very interesting. On another note, I find the service that they offer to be quite intriguing, and was wondering if anyone here has tried them out? what did you think?

thanks.

John

[gastone]

Some of those values were crazy. TMPR had mag readings of 1000ppm from one sample and 1600ppm from another. This occured not just with the Tropic Marin but with all of the salts tested. Either buckets had stratified (assuming they didn't shake up the samples beforehand and I gotta believe that they did) which is easy enough to solve by jostling up the buckets when we get them and every time we mix up a new batch of water, QC is off at the manufacturing plants (easy enough to accept, just look at what's going on with RC lately), the sample group was too small (2 per salt just ain't enough, and we can't expect a "independent" (won't even go there) lab to test 50 or 100 or 10,000,000 buckets to get a more accurate mean or median), or AWT's labs aren't up to par.

 

I'll continue to use what I've been using (IO mixed with oceanic - was going to switch to RC until...) and adjust the values according bucket to bucket. Sucks to have to supplement calcium, alk and mag, but that's the price of consistency IMO.

 

G.

 

Edit: of course my supplementing bucket to bucket is contigent upon the awful little home testing kits that we have at our disposal.

 

Edit: just read the commentary, apparently they didn't shake up the samples well, and to boot they didn't mix all of the samples up to NSW levels. They just mixed them at 7g per 200mL H2O, so that the salinity differed in all of the samples. Now if I want an (somewhat) accurate idea of what the measured parameters were I'd have to extrapolate the data to 35ppt. Yuck.

Edited February 11, 2008 by gastone

[dbartco]

Also kind of funny since those that buy Reef Crystals usually pay the premium for higher calcium and alk over the IO (for the salinity), and IO was the same or better in those samples. I know there is places to say it is flawed, but still interesting.

[madmax7774]

Edit: just read the commentary, apparently they didn't shake up the samples well, and to boot they didn't mix all of the samples up to NSW levels. They just mixed them at 7g per 200mL H2O, so that the salinity differed in all of the samples. Now if I want an (somewhat) accurate idea of what the measured parameters were I'd have to extrapolate the data to 35ppt. Yuck.

 

Did the math for reef crystals, since that is what I use. here's the computations:

Reef crystals instructions say to use 1/2 cup of salt per gallon. that works out to 114.96 grams(1/2 cup) of salt for 3,785.41ML (1 us gallon) divide both by 10 to scale down, and you get 11.49 grams of salt for each 378.5 ML of water. scaling that down for 7 grams of salt, comes out to 230 ml of water. Since they used less water than the reef crystals manufacturer recommends, then in my mind, that means that the values they published are actually a bit on the high side from real world results. That just sucks. What it really boils down to, is that since the salt product yields lower than expected results, then consumers have to use higher concentrations of it to get good results, which means the stuff doesn't last as long as it should. Seems like a benefit to the manufacturers as it probably lowers cost of production, and increases demand. That's just downright shady.

:( :(

[flowerseller]

I have no clue where the thread is but I tested several batches of I/O @ my house for giggles over the course of a couple of weeks.

I was suprised how well and relatively consistant it tested.

I followed my same routine of 1.026SG mixed for at least 24hrs.

I still think those of us with kalk and Ca reactors are better off with I/O instead of I/O-RC.

The same applies to someone who is very reliqious about adding 2 part.

 

Thanks for the link John.....

btw, don't I owe you a frag?

[treesprite]

I recently switched from reef crystals to IO and noticed the difference in how much salt I was having to use

[madmax7774]

Thanks for the link John.....

btw, don't I owe you a frag?

 

I don't remember you owing me one, but I would certainly be willing to come over and go shopping at Chip's frag center...

For some odd reason, the frags I get from you grow faster than anyone else's!!

[dshnarw]

I posted this on another forum, but it warrants it here as well. Basically stated, I have lots of issues with their work, the first few of which are below:

 

First, they state up front that they aren't doing it with any scientific validity:

 

This data was gathered

and is being shared in the spirit of community and is not meant to be a definitive scientific paper on this subject

 

and while I appreciate their effort to spark debate, what is the real use of this paper without scientific merit?

 

Secondly, though they admitted it wasn't for any scientific value, their testing procedure worries me, specifically that they only ran two (in some cases only one) sample(s) of each salt mix. Error, even with high precision equipment is high. Their standards aren't listed to compare their test values with the accepted values, their methodology is missing several key elements (for example, if they ran on different days, if they made all the salt mixes then ran them all, etc.

 

Finally, there is no way to compare the products because they all mixed up at various salinities. Since aquarists use salinity as a baseline for mixing salt, the only real comparison would have each salt at the correct salinity. In their tests, salinity varies from below 30ppt and up to 33ppt, or about .04 in SG units. Thus, direct comparison is impossible, and their entire series of graphs is essentially useless for any comparison.

 

 

So basically - even calculating their numbers for 35ppt for direct comparison, the small sample number leads to very large statistical uncertainties, even in very high precision equipment, and we have no idea what their standards measured at or how their data was corrected, so the numbers could be spot-on, or the errors could be so large that every salt actually tests exactly the same.

[Highland Reefer]

I have been using Reef Crystals. I have to increase calcium, ph & kh pretty much as what the test results show. I just bought Instant Ocean due to the price difference. I have been testing the Reef Crystalls everytime I do a water change with the same readings each time. It will be interesting to see what I get for the readings on Instant Ocean.

 

Great Article, I would like to see a broader base for the samples.

 

I wouldn't mind having my water tested once, just to see how accurate my tests are. The price is not that bad for what you get. If you go to the lab in Rockville, MD to have tests done, their prices are much, much more. I have used this lab to have my well water tested.

[dshnarw]

Ok, so I did some adjustments to get them to 35ppt, since normally I mix my water up to 1.025-1.026, and it seems that being able to compare that way would be more useful as a comparison (though I still have issue with the stuff I posted previously).

 

These will all be the adjusted values, in order of: Ca, Mg, Alk

 

Reef Crystals: 386, 1263, 3.5

Tropic Marin: 309, 1329, 3.17

Tropic Marin Pro: 381, 1486, 2.84

Oceanic: 531, 1343, 3.88

Coralife: 529, 1455, 3.38

[steveoutlaw]

I don't remember you owing me one, but I would certainly be willing to come over and go shopping at Chip's frag center...

For some odd reason, the frags I get from you grow faster than anyone else's!!

 

 

Must be the salt!!

 

Now my question......I have been using Reef Crystals for quite a while. How should I switch over to regular IO? Do I need to do a half and half mix? 1/4 IO to 3/4 RC?

 

Thanks.

[flowerseller]

If it was me. I'd 50/50 until your RC is gone doing small W/C weekly as opposed to big W/C monthly.

If you're using a kalk and/or a Ca reactor, using RC ( or really any other salt ) won't matter much.

[steveoutlaw]

I do have a kalk reactor that all my ATO water runs through.

 

I only have enough RC for a 5g water change. Looks like I'm going to have to buy a little more RC when I get my 5g bucket of IO.

[madmax7774]

I am following the same line of thought as steveoutlaw. I am going to switch over to IO. No point in spending the extra cash for RC if the darn stuff is no different than IO.

[flowerseller]

I do have a kalk reactor that all my ATO water runs through.

 

I only have enough RC for a 5g water change. Looks like I'm going to have to buy a little more RC when I get my 5g bucket of IO.

 

Steve,

I don't think you need to buy anymore RC.

Just do small W/C with the IO for a couple weeks and you'll be fine.

I really don't think you have that much to worry about in this change over

so take a break from being too hard on yourself.

[jnguyen4007]

LOL

 

Once again I have to thank YBeNormal for recommending me buying IO salt instead of one of the other more expensive brand that turns out to be no better and cost much more.

 

Dang! I just hate thanking that man so often for all the great advice he gave.

 

[dshnarw]

so after some communication with them, they did two different tests - the first to see what the salt mixed up to generally using the 1/2 cup per gallon rule. The second test, they mixed the salt to NSW conductivity (why not salinity, I have no clue), and ran the tests for everything in the graphs (except salinity and conductivity - those are from the first test).

 

With that info, I adjusted their values to 35ppt, under the assumption that conductivity and salinity were directly proportional (not true, but as close as we'll get for approximations).

 

The results are quite interesting and, to me, discount the entire article as, well, crap...

 

For example - according to the numbers, IO has HIGHER Ca values than Reef Crystals, Tropic Marin, and Tropic Marin Pro.

 

[gastone]

Dan, thanks for doing this... however it seems that now AWT is saying that the samples were in fact callibrated to 53mS, meaning your table is for naught and the original values posted are the ones we should be using.

 

http://reefcentral.com/forums/showthread.p...13#post11834713

 

I think.

 

Or at least I think that someone else thinks this, or I believe that someone believes that someone else thinks this may or may not be true.

 

I'm confused all over again.

 

I think I'll just use morton's for my next water change.

 

Garrett.

[dshnarw]

Dan, thanks for doing this... however it seems that now AWT is saying that the samples were in fact callibrated to 53mS, meaning your table is for naught and the original values posted are the ones we should be using.

 

http://reefcentral.com/forums/showthread.p...13#post11834713

 

I think.

 

Or at least I think that someone else thinks this, or I believe that someone believes that someone else thinks this may or may not be true.

 

I'm confused all over again.

 

I think I'll just use morton's for my next water change.

 

Garrett.

 

I'm honestly not sure what they did at this point, either. They've changed the story/wording around so many times that it doesn't make sense. Morton's may be the best bet

 

If this IS, indeed, what they did, 53mS is not a salinity for the salts of 35ppt based on their own calculations for the "yield test" as I think they're referring to it. So something is going wrong in the numbers somewhere. I've given up working through the various scenarios

 

so...I'll just stick to my cheapo RC and add some calcium and magnesium as needed

[gastone]

Was looking around and came across this

 

These guys did a pretty good job. Would be nicer to see more test kits used, but then again outside of a few outliers they do seem to be fairly consistent. Mostly my test kits ran out a few years ago, though I do check for calcium every now and then (I just assume as I use kalk for my topoff that my alk level is balanced in relation to my calcium level). Seeing how the APIs are comparable to the more expensive kits I ordered a few of them from the good Drs.

 

 

G.