Backyard Aquaponics
A place to discuss aquaponics

I know the water testing we do where we send away samples to labs for testing we get 3 bottles and 1 bottle has a chemical in it that kills everything and stop certain processes continuing for postage. Cant remember if its the dissolved metal testing bottle or not.

Might be something to consider, whether people will need to add some formaldehyde or something to their samples for shipping.

I have a YSI 9500 - so if you have any specific questions... fire away

What would the postage be from Florida?

The biggest question would be why did you get that one?

You have said previously that it is the only one that can measure Fe in a particular chelated form (I forget which one) or was it that it was the only one that could deal with the colour?

What is good about it?

What is not good about it?

I like the YSI 9500 for a few reasons:
1) It has more chemistries than the competition. This is because of #2
2) It has 6 wavelengths it can measure at. Hach only has 4.
3) The user interface is super-easy to work with and understand.
4) When you "blank" the meter, it blanks the meter at all wavelengths. You won't need to re-blank the meter for that testing session, unless you change dilution.
5) The reagents are all tablets. You open up the foil packet, drop the tablet in the test tube, and crush it up with a little plastic tool they provide. No counting drops or measuring.
6) If you use Fe-EDDHA or Fe-HBED (the ones that turn your water red), their mid-range test is the only iron test on the market that out-of-the-box will give you accurate results.

The bad
1) It's hard on batteries. It'll run off USB power so I try to keep it plugged in when i'm using it.
2) It's much bigger than a Hach DR900.
3) No Nickel test.
4) Boron test is no longer available (as far as I can tell).

The boron issue is a bummer. But Hach's boron chemistry requires a spectrophotometer, and uses sulphuric acid so they recommend using a fume hood as well. The LaMotte Smart3 has a boron chemistry, but for now i'm just using my Hanna HI38074 for boron titrations.

Yeah Hach one didn't look very good at all.

What about stepping things up to the scanning spectrophotometers. They are much more expensive but is there any value for us?

The added value in a spectrophotometer is minimal. You can get a small amount of extra precision, which is usually not needed. With Hach models, higher end ones promote the use of TestNTube or ampules where the reagent is pre-measured out, the machine reads the barcode on the vial to know which test to run, and automagically re-reads the test 10 times to ensure data quality.

With an UV spectrophotometer you can read Nitrate without using reagents... but that's not worth the additional expense in my opinion.

Oh the other hand, they look really cool. Sitting there, gathering dust, and depreciating.

What would be even cooler would be a gas chromatograph

Would the bottle that is dosed be for testing THMs(tri halo methanes)? A by product of chlorination. It has ammonium chloride added to the bottle to quench the chlorine/chloramine, so the THMs don't change over time.

Or is it for ecoli or coliforms, the bottle is dosed with sodium thiosulphate, to again quench the chlorine. Must be in a sterile bottle.

If it's for heavy metals, the bottle is acid rinsed to remove any potential contamination from the plastic.

Most other sample bottles do not require any pre treatment or bottle dosing. Ie for nutrients(some samples are pre filtered and frozen before analysing), biological(algae), organics, etc.

They do though have holding times(from 24hrs to a month for the more stable compounds) and are required to be chilled for transport to ensure integrity before testing.

BTW, what lab do you send your samples to?

Well its looking like its a YSI 9500. That is the conclusion I had come to the only thing that was causing me to hesitate was the reagents.

I'll chase up how much those are on Monday. I've found one website that sells them but their range is rather limited.

I know we need to get some more details, but can we get a show of hands on who is interested?

I might have just wrangled a job that will give me some cash to put in

Congratulations!

Huzzah, though might not be as cheap if it's just me and you Stu haha

I've found a supplier online for the reagents. Actually remembered would be more accurate because its one of the guys I've got a wholesale logon for.

I've added details of the cost per test for the reagents.