I'd like to replace my filter's tubing, but it's so much cheaper at a hardware store than from the filter manufacturer...
Are there any particular concerns to using something from Home Depot, etc..? Does it need to be made from any specific material?
When you measure the diameter of tubing, is the listed measurement considered the exterior width, or the interior width?
I haven't tried it on aquariums since I haven't needed to. I have had issues in a pond though. Some of the hardware stuff hardens up way more than aquarium tubing and can pop off. Luckily this is not as much of an issue in a pond, depending on where it pops off, but won't flood your room. I am not sure if it was a temperature thing but I did have a mix of Eheim tubing and hardware tubing and the Eheim did much better. Both were affected by UV too, that may have played a role but my Eheim stuff held up better, even though it was sun bleched to a very dull, almost clear yellow. I don't know if you would have the same issues indoors with much higher temps and less UV, but I did notice a difference outdoors. I only tried 2 brands, they may have been the same brand in different colors but it's made me weary of it.
You would go off the interior diameter. Not all tubing has the same "wall thickness" so you can have the same inside diameter but the outside diameter may be thinner, or more thick.
I don't want to discourage you from using the hardware stuff, I am just saying that I found a noticeable difference in a non name brand, without any research, in a way more extreme environment. We are talking about temps from maybe 28 degrees to 110 degrees, full sunshine for a lot of the days. I do hope someone chimes in on a brand or store to help you, and maybe myself in the future.