API test tubes

Thanks, it sounds simple but convenient.
 
Here are some pics of the rack I made. Eggcrate held together with twist-ties/zip-ties. I offset another piece on the bottom to keep the tubes from falling through. Waterproof, washable, lightweight, handy, etc.
I also have a child's eyedropper for dosing meds or ferts that sits in there. You could make it to hold however many you want
.tuberack1.jpgtuberack2.jpgtuberack3.jpgtuberack4.jpg

tuberack1.jpg tuberack2.jpg tuberack3.jpg tuberack4.jpg
 
AquariaCentral.com