Help Me Solve My Mystery

[PMS Woody]

So i've been doing some searching and reading about the API tests. I have found that the .25 ammonia reading problem is a common one. Apparently, if you don't properly dry your test tubes in between tests (I'm guilty of this) then you get a false reading of .25 but if you dry your test tubes properly then you get an accurate reading.

Oh wow... I'm guilty of that too! What do they suggest drying them with? They aren't exactly easy to get into!

 

[Essjay]

I always wash and dry mine carefully. It's easy. I use a paper hanky. Take hold of one corner, smooth the rest of the tissue away from the corner then twist it round and round. Now poke the thin twisted bit into the tube, push down as far as you can and rotate it round inside the tube till all the blobs of water have been soaked up. One corner will dry two tubes. For more, just repeat with the opposite corner. One tissue will dry four tubes. And dry the lids with the middle bit, pushing it into the grooves with your fingernail.
Don't forget to wash the tubes thoroughly first! My routine is empty, fill with water and empty twice, half fill, shake well and empty three times (covering with your finger is safe at this point), drain upside down till all the tubes are washed then dry as above. Lids are just held under running water for 10 seconds.

Sorry if this sounds a bit patronising, teaching your granny to suck eggs as the saying goes, but this is how I washed my glassware as a chemistry student many years ago.

 

[lisa2701]

Well I think air/drip drying them is the best way to do it. No doubt you could roll up a small bit of kitchen roll or use a hair dryer if you needed it quickly?

Last night I cleaned out my tubes thoroughly (noticed the nitrates one has stained slightly orange) and then left them sat up side down over night. Tested this morning and checked in day light and the results are...

Ammonia: 0.00pp (yahoo)
Nitries: 0.00ppm
Nitrate: 20-40ppm (this was hard to read as theres a big jump in colour between 20 and 40 and it didn't fit either, i'm guessing 30ppm).

So I am thinking the ammonia has in fact been 0 all this time as when I looked at this mornings test under a household light it looked like it had a greeny tinge!

 

[lisa2701]

I always wash and dry mine carefully. It's easy. I use a paper hanky. Take hold of one corner, smooth the rest of the tissue away from the corner then twist it round and round. Now poke the thin twisted bit into the tube, push down as far as you can and rotate it round inside the tube till all the blobs of water have been soaked up. One corner will dry two tubes. For more, just repeat with the opposite corner. One tissue will dry four tubes. And dry the lids with the middle bit, pushing it into the grooves with your fingernail.
Don't forget to wash the tubes thoroughly first! My routine is empty, fill with water and empty twice, half fill, shake well and empty three times (covering with your finger is safe at this point), drain upside down till all the tubes are washed then dry as above. Lids are just held under running water for 10 seconds.

Sorry if this sounds a bit patronising, teaching your granny to suck eggs as the saying goes, but this is how I washed my glassware as a chemistry student many years ago.

This is exactly what I done last night, except I let it air dry but thanks for the tips .

Also, I have wondered - do you hold the test tube 'againt' the card when comparing the colours or 'just off' the card (they give slightly different readings) and it turns out you hold it 'against' the card . SOme clever little soul e-mailed API and asked all these questions and then posted their reply on the internet... very helpful!

 

[PMS Woody]

I always wash and dry mine carefully. It's easy. I use a paper hanky. Take hold of one corner, smooth the rest of the tissue away from the corner then twist it round and round. Now poke the thin twisted bit into the tube, push down as far as you can and rotate it round inside the tube till all the blobs of water have been soaked up. One corner will dry two tubes. For more, just repeat with the opposite corner. One tissue will dry four tubes. And dry the lids with the middle bit, pushing it into the grooves with your fingernail.
Don't forget to wash the tubes thoroughly first! My routine is empty, fill with water and empty twice, half fill, shake well and empty three times (covering with your finger is safe at this point), drain upside down till all the tubes are washed then dry as above. Lids are just held under running water for 10 seconds.

Sorry if this sounds a bit patronising, teaching your granny to suck eggs as the saying goes, but this is how I washed my glassware as a chemistry student many years ago.

Well I think air/drip drying them is the best way to do it. No doubt you could roll up a small bit of kitchen roll or use a hair dryer if you needed it quickly?

Last night I cleaned out my tubes thoroughly (noticed the nitrates one has stained slightly orange) and then left them sat up side down over night. Tested this morning and checked in day light and the results are...

Ammonia: 0.00pp (yahoo)
Nitries: 0.00ppm
Nitrate: 20-40ppm (this was hard to read as theres a big jump in colour between 20 and 40 and it didn't fit either, i'm guessing 30ppm).

So I am thinking the ammonia has in fact been 0 all this time as when I looked at this mornings test under a household light it looked like it had a greeny tinge!

I don't leave mine sealed and full or anything. I thoroughly rinse them and lean them upside down on a 15 degree angle to dry. Was never a chemist so I think its fair to ask "how clean is clean"!

 

[lisa2701]

Good question woody, especialy since you can't exactly use soap or anything to aid the cleaning process. I am 100% sure that I was just reading the tests under the wrong light , i'm not the brightest bulb in the box am I sheesh. My filter IS indeed processing 2-3ppm in approximately 12 hours, meaning that it has been since i got it (I got it already cycled) .... so I am thinking some little fishes are needed for this empty tank!!

 

[Essjay]

I don't leave mine sealed and full or anything. I thoroughly rinse them and lean them upside down on a 15 degree angle to dry. Was never a chemist so I think its fair to ask "how clean is clean"!

Rinsing with plain cold water is the best you can do in the home. I empty the tube then fill to the top with tapwater and empty twice. This gets rid of most of the test water + reagent. Then I half fill with tap water, put my finger over the top and give a very good shake to loosen anything that might be stuck to the glass, empty and do that twice more. So 5 rinses and 3 shakings in total. This should remove anything sticking to the glass and rinse everything away. But leaving the tubes to dry will leave a deposit of some sort behind, even if it's just the minerals present in tapwater. That's why I leave the tubes upside down for a few minutes to drain most of the water then dry with a paper hanky.

If you really want to make sure the tubes are clean they you could use a small bottle brush, but I'm a bit wary of doing that as the tubes aren't the most robust glassware I've come across. I'd be terrified of breaking them. In the lab, we also used to do a final rinse with acetone which removed the water and dried very quickly, but you can't do that at home. It's probably not done in labs either nowadays - I was at univeristy a few decades ago!

 

[Essjay]

Forgot to mention yesterday - when drying the tube with a tissue, if there is any staining on the tissue, I wet the tissue and clean the tube as well as I can with it, then rinse as above and dry again. Usually this only happens if I leave the tubes for a couple of hours before I remember I haven't washed them. Washing within half an hour-ish doesn't normally result in staining.