Testing for organics

[Aquaman_68]

Is the club water testing area set up to get readings in the PPM range for organics? If not what would it take to get what we need?

[Jim Tansey]

What organics would you like to test for?

Jim

[Aquaman_68]

TOC's (total organic coumpounds)

[Greg Hiller]

We have no organics kits in the club's chemistry lab. Can you suggest a kit or testing method? Any you've worked with? Have any of them given you data that propted you to make a change in your tank? I'm not judging here at all, I just know very little about the kits/methods that are out there, and trying to determine if the club should invest.

[Matt L.]

Just caught this threrad now.

There are several tests for TOC.

If you're really interested, you could give me a sample and I could have it run here. We have a Teledyne/Tekmar automated TOC analyzer. What range do you think you're in?

Matt:cool:

[Aquaman_68]

Just caught this threrad now.

There are several tests for TOC.

If you're really interested, you could give me a sample and I could have it run here. We have a Teledyne/Tekmar automated TOC analyzer. What range do you think you're in?

Matt:cool:
I'm looking to test down to 1ppm. Target range for an established SPS Reef is 1.4 ppm. Just want to see if I'm in the target & I was wondering if the club planned on getting a device/equipment to test for TOC's.
LMK by pm, Matt.
B

[Matt L.]

I'm looking to test down to 1ppm. Target range for an established SPS Reef is 1.4 ppm. Just want to see if I'm in the target & I was wondering if the club planned on getting a device/equipment to test for TOC's.
LMK by pm, Matt.
BWell, I think there are colorimetric tests that run about $300, but you're down in the very low range for TOC, and thus probably won't get much accuracy. You'll also need a spectrophotometer. I have one at home that I could let the club borrow, but I'm not sure how well it's working. Otherwise, you would have to provide me with a sample, and I'd have to have it analyzed on a TOC analyzer, which at $20,000+, is probably outsiude the range of the club's budget.

Matt:cool:

[Greg Hiller]

>at $20,000+, is probably outsiude the range of the club's budget<

Ah.....yup!

[Matt L.]

But I can get you a scientific analysis for free.

Matt:cool:

[Aquaman_68]

But I can get you a scientific analysis for free.

Matt:cool:
So if I got you a sample could you test it for me? :o

[Matt L.]

Yeah, sure. Can you stabilize it (add 1:300 v/v conc. H2SO4 and place in amber bottle)? If not, just put it at 4C and bring it to me on ice and I can stabilize it. Stabilized TOC samples are good for one month in an amber bottle.

Matt:cool:

[dz6t]

The reason behinde the test is?
May be you should test the natural sea water around reef as a reference point.

[Aquaman_68]

The reason behinde the test is?
May be you should test the natural sea water around reef as a reference point.
If you have to ask than it seems fruitless to answer. (You may want to re read the entire thread, Dong)
I don't need to test NSW around a reef for a reference. I already know what the organic levels are in a wild SPS farm. If you don't please send me a pm & I will enlighten you!!

There's a good point to be made about this forum...If you don't understand something please shoot someone a pm instead of clogging up a thread with suggestions!!;)

[Matt L.]

Dong,

A great deal of research (outside of the hobby) focusses on dissolved organic carbon, organic nitrogen, and organic phosphorus in the environment.

These compounds are often not biodegradable at first glance, and are often termed refractory. It is suspected that many come from human activity.

However, these refractory organics may be later broken down releasing nutrients under the right conditions.

In other words, it is possible for us to have reservoirs of organic nitrogen and phosphorus built up in our tanks from a period, and then later have them slowly broken down releasing nitrogen and phosphorus into our water.

Matt:cool:

[dz6t]

I understand the concept regarding organic content dissolved in water and its effect. I question the testing method and what the result can guide you or mis-guide you.

[Matt L.]

Dong, I agree that using a colorimetric method could yield imprecise results, but an automated TOC analyzer is more than capable of accuraltey assessing TOC levels in the 1ppm order.

Matt:cool:

[MikeG]

http://www.reefkeeping.com/issues/2004-10/rhf/index.php

[Matt L.]

http://www.reefkeeping.com/issues/2004-10/rhf/index.phpI had not previously seen that article.

To quote Dr. Randy Holmes-Farley's Conclusion:
In my opinion, organic materials are one of the biggest chemical mysteries in reef aquarium husbandry...

Hopefully, reef aquarists of the future will have a better handle on what is happening with organics in their aquaria. I talked to a number of professional chemists at the recent MACNA conference in Boston, and several indicated a willingness and capability to begin addressing these issues. To get such folks started, we need to figure out what the most pressing issues are that are solvable with currently available technologies. Once that has been determined, it is largely a matter of time and money before useful results might be obtained.Dr. Randy Holmes-Farley is not alone in his sentiment. As I expressed above, dissolved organic matter is an exciting and pressing area of research outside the hobby. My current research focusses are on the availability of refractory dissolved organic nitrogen to model eutrophying algae. I am more than capable of getting a few DOC tests done, and if we get a survey of reef tanks, we could possibly present this data.

Matt:cool:

[MikeG]

Although an old article, I thought it gave people some ideas as to why you might want to do some investigation.

This is one thing I found of interest there

"Another drawback to organics that are taken up by bacteria and other organisms is that in order to metabolize them, such organisms use oxygen (if they are aerobic organisms). Equation 1 (above) shows the net effect of what happens when organics are metabolized. For each carbon atom in a typical organic molecule in seawater, 1.3 oxygen molecules are consumed. At levels of DOM in natural seawater, on the order of 1 ppm, this result implies that oxygen would drop by 3.5 ppm if it were all fully oxidized. Obviously, not all of the carbon will be rapidly and completely oxidized, but if organic levels are appreciably higher in some aquaria than in the ocean, then the oxygen depletion potential may be very important relative to normal saturation levels on the order of 7 ppm oxygen."

[Greg Hiller]

Matt,

>Yeah, sure. Can you stabilize it (add 1:300 v/v conc. H2SO4 and place in amber bottle)?<

Or add the acid and wrap the plastic tube in aluminum foil? How much volume do you need? I could bring some acid to the next meeting and you could have yourself a bunch of samples if you really wanted.

[Matt L.]

Let me see... I'll see if I can make it to the July meeting. I can definitely make it to the August meeting. I can bring the bottles with acid already in them. Typically, we take 300mL.

Matt:cool: