API REPLACEMENT TEST TUBES WITH CAPS For Any Aquarium Test Kit Including API Freshwater Master Test Kit 24-Count Box

Just as expected.

They work with the API water test kits, which is all I needed. Took a star off because not all of the lids are leak-proof, which can be an issue for the tests that require shaking vigorously like nitrates.. but all of their test tubes are like that, so oh well.

Needed more than just the 4 tubes included in the master test kit. This was exactly what I needed!

As a long time goldfish keeper, these are my absolute favorite for water testing. I like having extra on hand because the caps begin to lose their grip after long time use and the water will come out when you shake them up. I feel like a scientist when I use them and Im overwhelmed with power having so many on hand

Replacement API test tubes. I dont have the actual 24-pack, but I have plenty from purchasing individual tests and kits. Standard borosilicate glass. The caps wear out fast. They stop sealing as tight, and you will find yourself splashed with drops if you vigorously shake them, requiring you to put extra pressure on the cap to keep all of the liquid in. If you clean them with diluted bleach solution, it will dissolve the paint on them, so beware of that. The price for a replacement pack is ridiculous, and API doesnt sell them in any lesser packages at retail unless you go thru them, then its $2 per test tube. Edit: I have since purchased a pack of these, but my review remains unchanged.

Very helpful when you have more than one tank!

when you have multiple tanks and want to do all the water tests all at once. these are a must have!

Accurate to 5ml line. Tops are just a bit leaky like mentioned. Most irritating to me was I only received 22 of the 24.

I have the API Freshwater Master Test Kit, which comes with 4 test tubes. I do test for all five parameters on my potentially overstocked tanks before and after water changes. Having these extra test tubes makes it easier for me as I do not have to wash out my test tubes as I am conducting my testing on my tanks. Also, I have a before and after standard available to me for straight comparison. I tried using various vials and such (free stuff) to do my water tests, but the colour comparison with the API chart is best visible using API standardized test tubes. I would recommend that every aquarist/fishkeeper get themselves a set of these test tubes. Makes life a lot simpler.

These are the exact same tubes that come with the testing kit, which is what I wanted. I was happy to see that. In general, I think these tubes are kind of delicate, but I think my expectations of them are too high. They probably shouldnt survive a fall from the counter onto tile ;) But the tip-over on the counter itself broke one and annoyed me. But I bought a test tube rack, so I think Im good now. Shouldnt have any fall again :)