Backyard Aquaponics
A place to discuss aquaponics

Hi all,
Just needing confirmation that I'm reading my tests correctly... Should the tube be placed against the card or held alongside or just above the card? It's probably splitting hairs but when the tube is in contact with the card or when held upright the colour is always slightly darker and could give slightly different readings - especially in the darker red spectrum. When the tube is laying flat the liquid is obviously thinner and lighter in colour... I also notice a difference when testing indoors under fluro lights and outside in the (overcast) daylight. Has anyone else noticed this or am I just being a colour-blind goose?

Here's a pic... I read it as pH = 7.4, Ammonia = 1, Nitrite = 0.25, Nitrate = 40
Just looking at it, it's actually easier to read the photo than real life! - Perhaps I answered my own question...

Any comments appreciated!

Sorry guys, didn't mean to make a new topic here... should have been under my system thread...

I don't know from the picture I probably would say the nitrite looks like 0 to me while the nitrate is too dark for me to be certain of (I find I can't really accurate judge anything above about 30.)
The ammonia actually looks a little higher than 1 to me and I would probably also run the regular pH test to cross reference since the pH is reading the bottom of the range for the hi range pH test. Problem with some of the tests is that when it hits the end of the chart, it could be that or anything beyond.

Thanks TC,
Nice to know an experienced opinion ... I see what you mean...
BTW, when you test do you lay the tubes flat against the card?
... and also do the tests deteriorate over time? For example if I do all the tests and then come back in half an hour to read them...

Agree ammonia looks a bit higher than 1 and yes definitely to a low pH test...

I tend to just place the tube on the white part of the card and compare them with the tube vertical...
And yes tests will deteriorate over time especially on a hotter day. If you leave it in the tubes for about
half a day, the liquid in there will become weird... but half an hour should be fine... for that matter,
I tend not to leave the liquid in there after the tests...

theres very specific instructions as to how to do these. I think all except the pH are 5mins, and the pH is immediately. You should be trying to do thins as consistently as possible, so the readings from one day to the next are comparible. certainly after an hour, they are completely wrong.

i would have said, no nitrite, >40 nitrate, 2 ammonia and PH 7.8. assuming they are all at the appropriate timepoint.

Cool, Thanks Ivan and Orcy!,
I'm married to a scientist and she says the same thing - consistency is a value.

I usually do my tests when I get home from work at 4:00pm and have a bit of a consistent routine...
Get home, pat dog, get computer, get kit and beer, get water, pour tubes, run tests, drink beer, play with dog, check tests, write up results, play with dog, get beer, check results again and wonder if I'm doing it wrong, drink beer, decide to ask forum later if I'm doing it wrong, clean tubes and pack up kit, read forum, go inside because it's too bloody cold!

Time lapsed between adding chemicals and initial reading of tests = 15mins (+ or - 10% for extra patting and playing with dog)

yep do a low pH, I hold my tests up and put the colour chart at the back and look through the solution even have 1 bar up and down the tube, when you can hardly see the card then thats the number you want, method 2 is to put the glasses on, but that amm chart is hard to read except when it's yellow

I always do it vertically and hole the test tube about 1cm in front of the white section of the card.. (on the rare occasion that I do a test. )

yep haven't tested for a while, haven't opened the ammonia test I bought a while ago, I reckon if everything looks fine, then it probably is, less stress that way, if something looks wrong with the fish mainly then do a test

You all crack me up... I'm trying to be all scientific and shit... but no worries. I see a consensus forming...

The drinkers have our process and the thinkers have their process. Sounds like me and Science Girl talking about housework!

I'm in the drinking camp right now... IE: Don't do a test that often and hold the tube as far away as is necessary to achieve a result!

Works for me!

BTW started a couple of paintings about AP... some small paintings about fish and AP tanks... and the landscape... should have a pic tomorrow... if I wake up!
(Listening to Warren Zevon)

Nocky is my friend... despite being 2 hours less drinking than me, he makes absolute sense ... I'm doing a low pH and trying to do 1 bar up... Science Girl say NO!... hjetgvbx,m cb ---90 shiit!/.... hjfriukryf,jhvjm ... oops I fell over!... and lost my glasses!

Yes to being consistent.
I have a little space in the spare room under a bright light where I do my tests so I can read them under a consistent light.

I usually hold the white part of the card against the test tube while I hold it at an angel so I am reading through the full part of the tube and compare. It really can be hard to judge some colors.

And if your pH is between 7.3 and 7.9, it usually means running both pH tests to be certain.

I usually set a little cooking timer to remind me to come back and read the tests that have to sit and then I make a point of rinsing out the test tubes once I've written down the readings.

Thanks TC, for being so far away yet so stabilizing... so, in your presence, I will now go out into the cold wilderness and do a low pH test - just to show my devotion to the cause... did I mention it's cold out there?
brb....