Backyard Aquaponics
A place to discuss aquaponics

and the the refractory characteristics of "colour blindness"

you need to remember this is a kit that costs less than $50 for 700 (or 800) tests. That is less than 7c a test. Unless you really need accuracy to +/- 1ppm you are going to end up with close guesstimates.

As Tamo said, the trend of each molecule that you are measuring is more important than the guessed amount. In aquaponics and in other fish keeping, you need to know if your pH is increasing, or if the ammonia is rising rapidly, not that there are 60ppt when there used to be 55ppt.

It did cross my mind. And, since most chemical reactions are based at a certain temperature, it is probably an assumption that the results will be the same at near freezing for example.

Have we confused him enough yet?

the length of time that you let the tube rest too will change the results.








This from the person who does not have a test kit

Seen evidence of that J, that is why I stick to the times as stated on the cards

put it this way...............if my test kit is yellow i'm happy

if it has a tinge of green then i inspect other things.

Wether its vivid green or dark green 4.0 or 8.0) doesn't worry me as the course of action will be the same and it should never be there anyway!

i dare say that volume DOES matter in the 2 reagent tests as they are a titration style test, and although a didn't do chem at school my understanding is............... known volume of sample with unknown conc. of what you are testing for + reagent 1 and 2 will give you a value of end product chemical which has a distinct colour at x conc.

therefore: if your original sample is the wrong volume then your end product sample will be out (becasue you are using know volumes (drops) of reagent.

same goes for the 1 reagent nitrite test.

The only one least affected will be the PH test as it will utilize a colour indicator that responds to ph and colour change is not usually in shades, more in actual colour..................

oh, and the reagents are prolly calibrated to the tube volume so keep them with their respective kits.

Yup ok ppl.
Problems were I wasn't measuring the meniscus at the right place, hence the vial size argument. Agreed, if I measure it correctly, they are all a lot closer to 5ml.
I don't have every test kit under the sun, it's just each of my 4 test kits for pH, NH, NO2 and NO3 are from different suppliers.
And each supplier specifies 5ml, but I was getting a discrepancy, because I wasn't reading the meniscus properly so the diameter of the vial made the error larger.
In the large vials, they say look down through the thickest part to identify the colour. This would be easier in a different sized tube in my opinion, hence my question.
Next I am not mixing colour charts and chemicals, only containers. the colour charts that come with the chemicals will be used with the chemicals, as I only have one set of each anyhow.
Does that clear up som misunderstandings?

Steve, to get a more accurate reading on nitrates, do you just add half the number of drops then double what the card says it is?

No, titration reactions are not linear. If you want a more accurate result, double the volume, double the reagents, and use a graduated titrating cylinder

I liked the chromatograph option too

Myself. I'm a mass spectrometer sort of guy

But for under $50 for 700+ tests, I'll stick with the masterkit

I just need a few extra genes as I am colour blind

Yeah - we understand KudaPucat , it was user error.

Well said CRTD. we went off on some tangents there when ppl just didn't follow that I F***ed up

Not quite, to dilute for better accuracy with nitrates:
1) take 200ml of fish tank water and place in a bucket
2) add 1.8litres of un-nitrated water (Janet uses distilled -check your tap water, mine is zero nitrates)
3) mix the 2 together then put 5ml into a vial
4) take normal reading then multiply by 10

Step 2 can be any figure compared to step1, just adjust the multiplier accordingly


Yeah it was good fun having at someone else for a change - normally it is me on the receiving end

wow, I was hoping it wasn't that much work no wonder most ppl don't do it

Thanks Les for the clarity.
KP- Did your Mum & Dad do everything for you?
Work I'd be surprised if you know the meaning of it!